Unit 3 BONDING and BIOCHEMISTRY Chemistry Interactive Notebook Table of Contents
Page
Date
Std
Learning Goal
Homework
Mastery/
Effort
10/7/13
10/8/13
10/9/13
10/10/13
10/11/13
10/14/13
10/15/13
10/16/13
10/17/13
10/18/13
10/21/13
10/22/13
10/23/13
10/24/13
Review for Exam
10/25/13
Unit 3 Exam
1
Unit 3 Bonding Study Guide
Chemistry Standard Set 2
Key Vocabulary Terms
1. Ionic Bond
2. Covalent Bond
3. Metallic Bond
4. Oxidation State
5. Coefficient
6. Subscript
7. Superscript
8. Metal
9. Non-metal
10. Neutrality
11. Electrostatic Attraction
12. Cation
13. Anion
14. Shared Pairs
15. Unshared Pairs
16. Outer Electrons/Valence Electron
Concepts
Orbitals – Filled – octet rule.
Energy – energy to form bonds, bond energy
Crystal Lattice – Alternating positive and negative ions to form ionic solids
Properties of Covalent, Ionic, and Metallic Compounds
Covalent – non-metals, lower melting points, non-conductor of electricity
Ionic – metal and non-metals, higher melting points, conductor of electricity
Metallic – metals, high melting points, conductor of electricity and heat, malleability, ductility,
reacts with acid
5. Neutrality in atoms and in the formation of formulas (sum of positive charge = sum of negative
charge). Ions are charged. Ionic Compounds are neutral.
6. Nomenclature- primarily ionic (nonmetal ending –ide) and some covalent (e.g., mono, di , and
tri)
7. Formation and Dissolving
1.
2.
3.
4.
Items for Memorization
Polyatomic Ions
Nitrate ion
Sulfate ion
Ammonium ion
Phosphate ion
Hydroxide ion
Carbonate ion
Bicarbonate
Permanganate
Chlorate
2
1-
NO3
SO42NH41+
PO4 3OH 1CO3 2HCO3 1MnO41ClO31-
Diatomic Molecules
Hydrogen
H2
Nitrogen
N2
Oxygen
O2
Fluorine
F2
Chlorine
Cl2
Iodine
I2
Bromine
Br2
Transition Metal Oxidation
States
Iron
Fe II and III
Copper
Cu I and II
Zinc
Zn II
Gold
Au I and III
Mercury
Hg I and II
Lead
Pb II and IV
Skills
1. Ability to predict bond types
a. Metallic
b. Ionic
c. Covalent
2. Ability to draw Lewis Dot Structures
Atoms (e.g., Na, Ba, Al, C, N, O, Cl, and Ne)
Covalent Compound (e.g., N2, O2, Cl2, and H2)
Polyatomic Structure (e.g., H2O, CO2, NH3, and CH4)
3. Ability to inventory compounds: Number and Type of Atoms
a. Al2(CO3)3,
b. (NH4)3PO4,
c. Ba(OH)2)
4. Ability to name ionic compounds given the formula and write the formula given a name (e.g.,
magnesium bromide, calcium hydroxide, iron III sulfate, and gold I phosphate)
5. Ability to name covalent compounds given the formula or write the formula given name (e.g.,
dihydrogen monoxide, carbon dioxide, carbon tetrachloride)
3
Unit 3 Bonding Fall Semester 2013-2014 Interactive Notebook Score Sheet
Quizzes/Formatives Date
Score/Max
Score
Retake Needed
(yes or no)
Peer Initial
Parent Initial
Formative 9 Bonds
Formative 10 Monatomic
Formula
Formative 11 Polyatomic
Ions
Formative 12 Polyatomic
Formula
Formative 13 Lewis Dot
Structures
Unit 3 Exam
Name of Scored Assignment
Date Due
Score/Max
Line Graph – graphic representation of continuous data.
Peer Initials
Level of Effort
Line graphs compare two variables. Each variable is
plotted along an axis. A line graph has a vertical axis and a horizontal axis. So, for example, if you wanted to
graph the height of a ball after you have thrown it, you could put time along the horizontal, or x-axis, and height
along the vertical, or y-axis. Vertical line will represent a day (x axis) and the horizontal line (y axis) will
represent progress on standards mastery with 5 advanced, 4 proficient, 3 basic, 2 below basis, and 1 incomplete
(y axis)
4
Electrostatic Forces and Ionic Crystalline Structure
Order the elements by increasing
electronegativity
Na, Rb, O, F
Order the elements by decreasing
electronegativity
Br, I, F, Sr, Ba
Electron affinity and Electronegativity
Elements with a high electron affinity also have high electronegativities. One term, electron affinity,
relates to attraction to gain an electron this is affinity. The other term electronegativity refers to
the pull of electrons once a bond has formed.
California Standard 2c. Students know salt crystals, such as NaCl, are repeating patterns of
positive and negative ions held together by electrostatic attraction
Description
The energy that holds ionic compounds together, called lattice energy is caused by the electrostatic
attraction of cations, which are positive ions, with anions, which are negative ions. To minimize their
energy state, the ions form repeating patterns that reduce the distance between positive and negative
ions and maximize the distance between ions of like
charges.
Prepare a labeled diagram to illustrate the description and
describe the organization of a NaCl crystal lattice.
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5
California Standard Chemical Bonds
2.
Biological, chemical, and physical properties of matter result from the ability of atoms to form bonds from
electrostatic forces between electrons and protons and between atoms and molecules. As a basis for understanding
this concept:
a.
Students know atoms combine to form molecules by sharing electrons to form covalent or metallic bonds or by
exchanging electrons to form ionic bonds.
b.
Students know chemical bonds between atoms in molecules such as H2 , CH4 , NH3 , H2 CCH2 , N2 , Cl2 , and
many large biological molecules are covalent bonds.
c.
Students know salt crystals, such as NaCl, are repeating patterns of positive and negative ions held together by
electrostatic attraction between ions.
d.
Students know the atoms and molecules in liquids move in a random pattern relative to one another because
the intermolecular forces are too weak to hold the atoms or molecules in a solid form.
e.
Students know how to draw Lewis dot structures.
f.
* Students know how to predict the shape of simple molecules and their polarity
from Lewis dot structures.
g.
* Students know how electronegativity and ionization energy relate to bond
formation.
h.
* Students know how to identify solids and liquids held together by van der Waals
forces or hydrogen bonding and relate these forces to volatility and boiling/ melting
point temperatures.
Think Pair Share – What are some meanings for the term bonding
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Metallic Bonds
6
Ionic Bonds
Covalent Bonds
Bonding Introduction (215-275 textbook)
Bonding occurs in order to become more stable. When a chemical bond is formed energy is released
because the resulting compound is more stable and at a lower energy state.
When energy is released the term exothermic is used. Exo means______________.
When bonds are broken energy is absorbed and the term endothermic is used. Endo means._________
A chemical bond is the force that holds two atoms together results from the simultaneous attraction
of electrons by two nuclei. Bonding only involves valence electrons. Atoms bond together to form
OCTETS (eight valence electrons) the most stable state. The exceptions are hydrogen and helium (2).
Standards Review Chemistry 2a. Students know atoms combine to form molecules by sharing
electrons to form covalent or metallic bonds or by exchanging electrons to form ionic bonds depending
on the atom’s electronegativity. Electronegativity - the affinity for electrons. Highest: Fluorine 4.0.
Covalent bonds between non-metals appears as a shared pair of electrons contained in a region of
overlap between two atomic orbitals, in the localized electron model. Atoms (usually nonmetals) of
similar electronegativities can form covalent bonds to become molecules. In a covalent bond, therefore,
bonding electron pairs are localized in the region between the bonded atoms. There are polar covalent
and nonpolar covalent bonds depending on electronegativity differences between the bonding elements.
Metallic bonds between metals. Valence electrons shared but not localized to individual atoms instead
electrons are free to move to temporarily occupy vacant orbitals on adjacent metal atoms, delocalized.
For this reason metals conduct electricity well. This kind of bonding is also called the sea of electrons.
Ionic bonds between metals and non-metals; occurs when an electron from an atom with low
electronegativity (e.g., a metal) is removed by another atom with high electronegativity (e.g., a
nonmetal), the two atoms become oppositely charged ions that are electrostatically attracted..

Cation metals tend to lose electrons and form positive ions called cations.
Ions formed are smaller than the neutral atoms because they have lost
electrons: Ionic radii < than atomic radii.

Anion nonmetals tend to gain electrons and form negative ions, called
anions. Ions formed are larger than the neutral atoms because anions
gain electrons: Ionic radii > atomic radii.
Chemical bonds between atoms can be almost entirely covalent (nonpolar), almost entirely ionic or in
between. The triple bond in nitrogen molecules (N2) is nearly 100 percent covalent as are other nonpolar diatomic molecules. A salt such as sodium chloride (NaCl) has bonds that are nearly completely
ionic. However, the electrons in gaseous hydrogen chloride are shared somewhat unevenly between the
two atoms. This kind of bond is called polar covalent.

Ionic bonds - formed between metal and nonmetal; created by a transfer of electrons;
Electrostatic Attraction to form neutral compounds; electronegativity difference > 1.7

Covalent bond - formed by the sharing of electrons between nonmetals; electronegativity
difference < 1.7.
Polar covalent bonds have electronegativity >0.3 and <1.7
Nonpolar covalent bonds have electronegativity differences <0.3


Diatomic molecules are considered to have NONPOLAR covalent bonding because their
electronegativity’s are the same and have zero electronegativity differences i.e. N2 𝑁
≡𝑁
Exception to 1.7 rule: METAL hydrides are ionic! ex. NaH
7
Compare and Contrast Covalent and Ionic Bonds
1. Define the following:
a. Electronegativity
b. Ionization Energy
c. Electron
d. Covalent Bond
e. Ionic Bond
f. Valence electron
g. Shared Pair
h. Lone Pair
i. Nonmetal
j. Metal
2. Using 7 of the 10 definitions you just wrote, compare and contrast covalent and ionic bonds. Underline key
vocabulary terms as they are used in your writing selection.
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8
Practice for Bond Type Formative
9
Properties of Compounds and Types of Bonds
10
Polyatomic Ions To Memorize
11
12
Lewis Dot Diagrams and Bonding
Draw the Lewis Dot Diagram below the following elements:
1. Magnesium
2. Potassium
3. Nitrogen
4. Neon
5. Aluminum
6. Sulfur
7. Lithium
8. Argon
9. Helium
10. What is an ionic bond?
11. What kinds of elements do ionic bonds form between?
12. Would Potassium (K) form an ionic bond with Fluorine (F)? Why or Why not?
13. Would Calcium (Ca) form an ionic bond with Neon (Ne)? Explain why or why not.
14. Would Nitrogen (N) form an ionic bond with Oxygen (O)? Why or Why not?
15. Would Calcium become an anion (-) or a cation (+)? Explain why.
16. Would Phosphorus (P) become an anion (-) or a cation (+)? Explain why.
2e. Students know how to draw Lewis dot structures
A Lewis dot structure shows how valence electrons and covalent bonds are arranged
between atoms in a molecule. Knowledge of the periodic tables allows the determination of
the number of valence electrons for each element in Groups 1 through 3 and 13 through 18.
Carbon, for example, would have four valence electrons. Lewis dot diagrams represent each
electron as a dot or an x placed around the symbol for carbon, which is C. A covalent bond is
shown as a pair of dots, or x’s, representing a pair of electrons or a line. For example, a
Lewis dot diagram for methane, which is CH4, would appear as shown in Figure 3.
13
DIRECTIONS: For each of the following, draw the electron dot structure for the atom and
identify the charge (oxidation state) of the ion it will form.
1.
Ba
2.
O
3.
Ga
4.
Cl
5.
He
6.
P
7.
Tl
8.
Li
9.
Al
10.
K
11.
Ca
12.
Ar
SECTION 2. Predict the chemical formulas for each of the following ionic compounds.
Example: Aluminum reacts with oxygen in air to form a whitish coating. Predict the formula
for the aluminum oxide formed.
13. K and O
14. Al and S
15. Ca and P
SECTION 3. CIRCLE THE ELEMENT IN EACH OF THE FOLLOWING IONIC COMPOUNDS WITH THE HIGHEST
ELECTRONEGATIVITY.
16.
MgCl2
17.
AlN
18.
HF
SECTION 4. CIRCLE WHICH ELEMENT IN THE FOLLOWING PAIR THAT IS MOST LIKELY TO LOSE AN
ELECTRON BECAUSE IT HAS A LOWER IONIZATION ENERGY.
19.
As or Se
20.
Kr or Ne
21.
Li or F
22.
H or He
23.
Fr or Rb
24.
B or O
25.
C or Ge
26.
Br or Sc
27.
Be or Mg
NAMING – IONIC COMPOUNDS. BINARY TWO ELEMENTS, TERNARY MORE THAN TWO ELEMENTS
Compound Name
Classification
Chemical Formula
Fe(OH)3
Pb3N4
Al2(SO4)3
Hg(OH)2
14
Chemistry: Chemical Ionic Bonding Activity
Introduction
When atoms bond together to form ionic compounds, they will not combine with just any other atom. For example, two
atoms that will never form an ionic bond are a sodium atom (Na) and a potassium atom (K). This is because both Na 1+
and K1+ are cations, or positively-charged ions. In order for two atoms to form an ionic bond, one must be a cation (+
charge) and the other must be an anion (- charge). Remember, opposite charges attract each other and similar
charges repel each other. Opposite charges can bond to each other and similar charges cannot. When opposite
charges are attracted to each other this attraction is called electrostatic attraction.
In this activity, you will get some practice in learning how atoms form ionic bonds. We will start with binary compounds
and end with ternary compounds. Listen carefully as the teacher explains the procedure, and then begin.
Identifying the charge different atoms will assume in order to have a stable electron configuration:
What will be the charge that the following atoms will assume and describe how many total electrons and how many
valence electrons and the overall charge of the ion:
Atom
Total electrons
Valence electrons
Ion Charge
Ion Symbol
Calcium
Bromine
Sodium
Aluminum
Oxygen
Pick two atoms, one a cation and one an anion and explain how a noble gas configuration occurred
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1. potassium and bromine
Compound Name _________________________________
WRITE THE EQUATION
Metal or Nonmetal
Ion Name
Ion Symbol
Anion/Cation
How Many?
Chemical Formula
15
2. oxygen and potassium
Compound Name _________________________________
WRITE THE EQUATION
Metal or Nonmetal
Ion Name
3. magnesium and bromine
Ion Symbol
Anion/Cation
How Many?
Chemical Formula
Compound Name _________________________________
WRITE THE EQUATION
Metal or Nonmetal
Ion Name
4. nitrogen and aluminum
Ion Symbol
Anion/Cation
How Many?
Chemical Formula
Compound Name _________________________________
WRITE THE EQUATION
Metal or Nonmetal
Ion Name
Ion Symbol
Anion/Cation
How Many?
Chemical Formula
The transition metals and other metals have variable charges so they have a special Roman numeral notation to
designate charge
Cation name
Charge
Cation symbol
Lead (IV)
Iron (II)
Copper (II)
5. lead (IV) and nitrogen
Compound Name _________________________________
WRITE THE EQUATION
Metal or Nonmetal
16
Ion Name
Ion Symbol
Anion/Cation
How Many?
Chemical Formula
6. aluminum and oxygen
Compound Name _________________________________
WRITE THE EQUATION
Metal or Nonmetal
Ion Name
Ion Symbol
Anion/Cation
How Many?
Chemical Formula
7 and 8. Make two compounds of iron (II and III) and oxygen.
WRITE THE EQUATION
Compound Name _________________________________
Metal or Nonmetal
Ion Name
Ion Symbol
Anion/Cation
How Many?
Chemical Formula
WRITE THE EQUATION
Compound Name _________________________________
Metal or Nonmetal
Ion Name
Ion Symbol
Anion/Cation
How Many?
Chemical Formula
9 and 10. Make two compounds of lead (II and IV) and sulfur.
WRITE THE EQUATION
Compound Name _________________________________
Metal or Nonmetal
Ion Name
Ion Symbol
Anion/Cation
How Many?
Chemical Formula
WRITE THE EQUATION
Compound Name _________________________________
Metal or Nonmetal
Ion Name
Ion Symbol
Anion/Cation
How Many?
Chemical Formula
17
Explain how you decide the formula and name when given two elements that form ionic compound.
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Ternary Compounds Practice
11. copper (II) and hydroxide ion
WRITE THE EQUATION
Compound Name _________________________________
Ion Name
Ion Symbol
Anion/Cation
How Many?
Chemical Formula
12. ammonium ion and nitrate ion
WRITE THE EQUATION
Compound Name _________________________________
Ion Name
Ion Symbol
Anion/Cation
How Many?
Chemical Formula
13. calcium and phosphate ion
WRITE THE EQUATION
Compound Name _________________________________
Ion Name
Ion Symbol
Anion/Cation
How Many?
Chemical Formula
14. ammonium ion and phosphate ion
WRITE THE EQUATION
Compound Name _________________________________
Ion Name
18
Ion Symbol
Anion/Cation
How Many?
Chemical Formula
Questions
1. What was the overall charge on all of the formula units that you constructed? Explain how this charge came to be.
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2. Evaluate the Periodic Table and answer these questions.
a.
Do nonmetals form anions or cations?______________________________________________________
b.
Do metals form anions or cations?_________________________________________________________
c.
What is the charge for all of the elements in Group 1?_________________________________________ ___
d. What is the charge for all of the elements in Group 2?_______________________________________________
e. What is the charge for all of the elements in Group 13?_______________________________________________
f.
What is the charge for all of the elements in Group 15?_______________________________________________
g. What is the charge for all of the elements in Group 16?_______________________________________________
h. What is the charge for all of the elements in Group 17?_______________________________________________
i.
Do cations bond with other cations? ____________________________________________________________
3. What type of elements (metals, metalloids, or nonmetals) form ionic bonds with metals?
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4. What type of elements (metals, metalloids, or nonmetals) form ionic bonds with nonmetals?
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5. Write the chemical formula that results when the following pairs of ions combine to form an ionic bond and the name
of the compound formed.
a. Sr2+ and O2-
b. Mn4+ and O2-
c.
Li1+ and Cl1-
d. Cs1+ and S2-
19
COMPOUNDS CRISS-CROSS METHOD
Write the correct formula of the ionic compounds formed between the positive and negative ions.
Cl
K
Ca
Al
Na
Cu+1
Fe+3
NH4
20
O
N
P
KCl
K3P
Potassium
Chloride
Potassium
Phosphide
S
Write formula and name the ionic compounds formed
CO3
NO3
SO4
PO4
OH
K
Ca
Al
Na
Cu+1
Fe3+
NH4
21
Ionic Bonding Review
1. Key Idea/s:
1d. Students know how to use the
periodic table to determine the
number of electrons available for
bonding.
b. Students can determine the number
of valence electrons present in a given
atom based on the element’s location
in the Periodic Table.
How do we know how many
valence electrons are in elements
2. Key Idea/s:
Students can explain that only the
outermost electrons [or valence
electrons] are involved in bonding.
What are valence electrons?
3. Key Idea/s:
Students know that either positive or
negative ions form and what these ions
are called
4. Key Idea/s:
Ionic Radii are different from Atomic
radii
How many valence electrons do
elements desire?
Examples:
2a has________
3a has________
4a has________
5a has________
6a has________
Which elements do not follow this
trend?
What kind of elements form ionic
bonds?
The number of valence electrons
are used to determine what?
How does an atom become a
positive ion?
How does an atom become a negative
ion?
How do ions form neutral
compounds?
When do ionic compounds form
Explain why cations get smaller than their
atomic form and anions get bigger than
their atomic form
5. Key Idea/s:
2a. Students know atoms combine to
form molecules by exchanging electrons
to form ionic bonds.
Discuss how dissolution breaks ionic
bonds
6. Key Idea/s:
2c. Students know salt
crystals, such as NaCl, are repeating
patterns of positive and negative ions held
together by electrostatic attraction.
7. Key Idea/s:
Students know the characteristics of ionic
compounds
22
What characteristics do ionic
compounds share?
How are ionic compounds different
than covalent compounds
8. Key Idea/s
Students can explain how electrical
conductivity occurs
How do ionic compounds conduct
electricity?
9. Key Idea/s:
How many potassium ions are
needed to balance the charge of
Students can determine the bonding
capacities of each atom[or element] by one sulfide ion?
examining the combining ratios of the
elements in the compounds it forms
Predict the formulas for:
calcium chloride
potassium phosphate
10. Key Idea/s:
Students can determine the bonding
capacities of each atom[or element] by
examining the combining ratios of the
elements in the compounds it forms
11. Key Idea/s:
What are polyatomic ions?
How many potassium ions are
needed to balance the charge of
one sulfide ion to form a neutral
ionic compound?
How many calcium ions are needed to
balance the charge of phosphate to
form a neutral ionic compound?
Ammonium
NO3-
Sulfate
CO3-2
Hydroxide
12. Key Idea
2e. Students know how to draw
Lewis structures
Draw K and Cl
Draw KCl
What is the formula for Aluminum
sulfide
Name MgO
Name Na2SO4
23
Standards Review Chemistry 2b.
Students know chemical bonds between atoms in molecules
such as H2, CH4, NH3, H2CCH2, N2, Cl2, and many large biological molecules are
covalent.
Organic and biological molecules consist primarily of the non-metals: carbon, oxygen, hydrogen, and nitrogen. These elements share
valence electrons to form bonds so that the outer electron energy levels of each atom are filled and have electron configurations like
those of the nearest noble gas element. Noble gases, or inert gases, are in the last column on the right of the periodic table and have
complete outer shells filled. Non-metals forming bonds with other non-metal elements tend to form covalent bonds. Non-metals
bonded together form covalently bonded molecules.
For example:
Nitrogen has one lone pair and three unpaired electrons and therefore can form covalent bonds with three
hydrogen atoms to make four electron pairs around the nitrogen.
Carbon has four unpaired electrons and combines with hydrogen, nitrogen, and oxygen
to form covalent bonds sharing electron pairs.
Diatomics: H2, N2, F2, O2, I2, Cl2, Br2 (Mnemonic for memorization: Have No Fear Of Ice Cold Beverages or the
diatomic 7)
1.
What is a covalent bond?
2.
What kinds of elements does it form between?
3.
Would Strontium (Sr) form a covalent bond with Chlorine (Cl)? Why or why not?
4.
Would Carbon (C) form a covalent bond with Neon (Ne)? Explain why or why not.
5.
Would Carbon (C) form a covalent bond with Oxygen (O)? Why or Why not?
6.
Show how Chlorine would bond to Chlorine what type of bond would be formed.
7.
Show how Carbon would bond to Hydrogen to form methane (CH4).
Properties of Compounds
Ionic
24
Covalent
Metallic
Practice Naming Covalent Compounds
1. Name the following molecules.
Prefix
Number
1
SF6
2
3
C4H10
4
5
CCl4
6
7
BH3
8
H2
9
2. Write the following formulas from the names.
10
Carbon tetrabromide
Heptanitrogen nonasilicide
Antimony pentasulfide
Disulfur decafluoride
In your own words, write the steps you would take to draw dot structures for molecules. Then draw the following:
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H2S
CH4
H2O
NH3
N2
CO2
H2O2
O2
F2
List the 7 Diatomic Molecules
25
Standard 10 Organic and Biochemistry Notes
Learning goals relate carbon chemistry to important biological molecules so that you
are able to describe 1) the versatility with which carbon atoms form molecules and 2)
the structure of organic and biological molecules and the polymers they form. Carbon
is the primary element of biologically active molecules needed for all living organisms
that live on Earth. In fact with few exceptions compounds containing carbon are
called organic compounds and those not containing carbon are called inorganic
compounds. There are certain trends observable that allow naming of organic
compounds and recognition of organic functional groups within compounds. Trends in
the periodic table are especially important and those pertaining to carbon include
nearby nonmetals and electronegativity.
The Elements
The six elements that comprise 99% of the mass of all living things are:
Carbon
Oxygen
Hydrogen
Phosphorous
Nitrogen
Sulfur (Sulphur)
Chemical bonds, especially covalent bonding and Lewis dot structures, are useful when considering chemical
structures that are biologically active. Recall the four biological macromolecules, protein, carbohydrate (CHO),
lipids (hydrocarbons) and nucleic acids (DNA, RNA CHO-N base-P) are carbon-based. Carbon forms single,
double, and triple bonds and nitrogen also forms covalent bonds with nitrogen and oxygen electronegativity used
to form organic molecules functional groups so important to the physical properties of amino acids and thereby
proteins.
Lactose - disaccharide
California Standards -10 The bonding characteristics of carbon allow the formation of many
different organic molecules of varied sizes, shapes, and chemical properties and provide the biochemical basis of life.
10a. Students know large molecules (polymers), such as proteins, nucleic acids, and starch, are formed by
repetitive combinations of simple subunits. Notice visualize representations of these large molecules called
polymers as consisting of repetitive and systematic combinations of smaller, simpler groups of atoms, including
carbon. All polymeric molecules, including biological molecules, such as proteins, nucleic acids, and starch, are
made up of various unique combinations of a relatively small number of chemically simple subunits. For example,
starch is a polymer made from a large number of simple sugar molecules joined together.
Four Biological Macromolecules
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Monomers that make up biological polymers
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26
10 b. Students know the bonding characteristics of carbon that result in the formation of a large variety
of structures ranging from simple hydrocarbons to complex polymers and biological molecules.
Building on what you learned about carbons four valence electrons and covalent bonding characteristics
whereby valence electrons are shared, carbon can form single, double, or triple bonds which affects molecular
shape/geometry. The variety of organic molecules is enormous: over 16 million carbon-containing compounds
are known. The compounds range from simple hydrocarbon molecules (e.g., methane and ethane) to complex
organic polymers and biological molecules (e.g., proteins, starches, carbohydrates, nucleic acids ) and include
many manufactured polymers used in daily life (e.g., polyester, nylon, and polyethylene).
Polymer Portion
Repeating Unit
10. c. Students know amino acids are the building blocks of proteins.
Proteins are large single-stranded polymers often
made up of thousands of relatively small subunits called
amino acids. The bond attaching two amino acids, known
as the peptide bond, is identical for any pair of amino
acids. The chemical composition of the amino acid itself
varies. Variation in composition and ordering of amino
acids gives protein molecules their unique properties
and shapes. These properties and shapes define the
protein’s functions, many of which are essential to the
life of an organism. The blueprint for building the
protein molecules is deoxyribonucleic acid (DNA).
Biotechnology is advancing rapidly as more is learned
about DNA, amino acid sequences, and the shapes and functions of proteins.
Central Dogma of Biology DNA transcribed into RNA translated into amino acid sequences. On ribosomes
dehydration condensation occurs to form peptide bonds between amino acids
27
Characteristics
High melting points (450 degrees and higher) are characteristic of ionic compounds but organic compounds
generally have low melting points. Wax and street tar melt in the summer heat; sugar melts and can burn on the
kitchen stove. Wax, tar, and sugar are examples of organic compounds.
Covalent or shared bonds are hard to break so many organic reactions proceed slowly.
Saturated hydrocarbons share a single pair of electrons (single bond). The hydrocarbon series -ane has a single
bond.
Unsaturated hydrocarbons have one or more double bonds or triple bonds (-ene has a double bond; -yne has a
triple bond; and alcohols have one -OH group at the end of a hydrocarbon).
Because carbon has 4 valence electrons, it can form 4 shared (covalent) bonds.
Trans Fats: The Science and the Risks1
This man-made fat was developed to protect us against butter. Turns out, it acts like butter inside
our bodies.
Trans fatty acids or trans fats are formed when manufacturers turn liquid oils into solid fats. Think shortening and hard
margarine. Manufacturers create trans fats via a process called hydrogenation. Hydro-what? In a nutshell,
hydrogenation is a process by which vegetable oils are converted to solid fats simply by adding hydrogen atoms.
Why hydrogenate? Hydrogenation increases the shelf life and flavor stability of foods. Indeed, trans fats can be found in
a laundry list of foods including vegetable shortening, margarine, crackers (even healthy sounding ones like Nabisco
Wheat Thins), cereals, candies, baked goods, cookies, granola bars, chips, snack foods, salad dressings, fats, fried
foods, and many other processed foods.
Trans fatty acids are found naturally in small quantities in some foods including beef, pork, lamb, butter, and milk, but
most trans fatty acids in the diet come from hydrogenated foods.
Like saturated or animal fats, trans fats contribute to clogged arteries. Clogged arteries are a sign of heart disease; they
increase your risk of both heart attack and stroke. Here's how it works: Trans fats raise low-density lipoprotein (LDL) or
"bad" cholesterol levels. This contributes to the buildup of fatty plaque in arteries.
Fractional Distillation. Because hydrocarbons differ in boiling points, fractional distillation separates the parts
(fractions) of the mixture by heating the hydrocarbons in long columns until they form gases (vaporization). At
various points in the tower the fractions (hydrocarbons) condense and are removed. This is possible because the
hydrocarbons have different boiling points.
Isomers
These are organic compounds that have the same chemical formula but a different structural formula, which
means isomers have different shapes and therefore behave differently.
Links
http://eppe.tripod.com/organic.htm
http://www.chemistrylecturenotes.com/
http://www.glencove.k12.ny.us/highschool/ChemRev/ChemRev.html
http://www.wwnorton.com/college/chemistry/gilbert2/chemtours.asp flash animation stories
1
http://www.webmd.com/diet/features/trans-fats-science-and-risks
28
Organic Chemistry Review
1.
What does the term organic chemistry mean? What does the term inorganic chemistry mean? Include an
example of both an organic compound and an inorganic compound in your discussion.
____________________________________________________________________________________
____________________________________________________________________________________
2. List the properties of organic versus inorganic compounds. Your discussion should include such things as:
bonding, melting and boiling point, solubility, and flammability.
_____________________________________________________________________________
_____________________________________________________________________________
3. Explain why carbon can form macromolecule polymers
__________________________________________________________________________
4. What is an amino acid and explain how they are bonded together
__________________________________________________________________________
Organic Chemistry Chemical Bonding in Alkanes
1.
Hydrogen has how many valence electrons?____ Draw its Lewis dot formula:
Carbon has how many valence electrons?____ Draw its Lewis dot formula:
2. Carbon likes to have 8 valence electrons when it forms molecules.
How many hydrogens are needed to make 1 carbon satisfy this "octet rule"? _____
3. A covalent bond is formed by two shared electrons. Draw the Lewis dot structure for
methane CH4
4. Re-draw the methane carbon-hydrogen, replacing the dots with straight line bonds:
Released Questions
29
Covalent Compounds Worksheet
1)
2)
3)
4)
Based on the properties of the following materials, determine whether they are made of primarily ionic
compounds or covalent compounds:
a)
telephone receiver: ______________________________________
b)
concrete: ______________________________________________
c)
gasoline: ______________________________________________
d)
candy corn: ____________________________________________
Name the following covalent compounds:
a)
SiF4 __________________________________________________
b)
N2S3 _________________________________________________
c)
HBr __________________________________________________
d)
Br2 __________________________________________________
Write the formulas for the following covalent compounds:
a)
diboron hexahydride ____________________________________
b)
nitrogen tribromide ______________________________________
c)
sulfur hexachloride ______________________________________
d)
diphosphorus pentoxide __________________________________
Write the empirical formulas for the following compounds: To find the empirical formula divide by the smallest
subscript number. This becomes the mole ratio of the elements and is represented by subscripts in the empirical
formula.
a)
C2H4O2 _______________________________________________
b)
boron trichloride ________________________________________
c)
methane ______________________________________________
d)
C6H12O6 ______________________________________________
5)
List three differences between ionic and covalent compounds:
6)
Explain why ionic compounds are formed when a metal bonds with a nonmetal but covalent compounds are
formed when two nonmetals bond.
30
Positive
ion
Negative
ion
Formula
Formula Mass
Molar Mass
1. Sodium Iodide
Na+
I-
NaI
22.99+126.9=149.89 g
2. Silver( I ) sulfide
Ag+
S2-
Ag2S
Name of Ionic Compound
3. Barium sulfate
4. Lithium sulfide
5. Sodium hydroxide
6. Zinc sulfate
Zn2+
7. Iron(III) phosphate
8. Nickel (II) hydroxide
9.
Magnesium phosphide
31
Note Taking Guide: Episode 5012
Chemical bond - forms when 2 or more atoms rearrange ____________ _____________ to increase
________________.
Ionic bond - forms when valence _____________ are _____________ from one atom to another
forming salts. Ionic bonds usually form between metal and nonmetal elements.
cation – atom __________ electrons to become ______ charged
anion - atom __________ electrons to become ______ charged
In ionic compounds the ions are arranged in a ___________ ___________.
__________ forces hold the ions together (these are electrostatic forces).
Properties of ionic compounds:
 high _________________ and_________________points
 ___________ - not easily ______________
 _____________ electricity when ___________ or______________ because the ions are
free to __________. Does not conduct electricity when a solid
Covalent bond - ______________ are _____________, forming _______________ held
together by covalent bonds. Occurs usually with non-metal elements.
Covalent compounds have ____________ forces holding the _____________ together.
Properties of covalent compounds:
• lower _________________ and _________________ points
• Many covalent compounds are _____________ liquids or gases.
• ____________– easier to ___________
• are not ________________ of electricity
Compound
Solid Conductivity
Dissolved in Water
Conductivity
Bond Type
Table Salt (NaCl)
Para dichloro benzene
Copper Sulfate (CuSO4)
Ethanol (C2H2OH)
Sugar (sucrose)
Selzer (NaHCO3)
Electronegativity - property that tells how strong an atom’s ____________ is for an
_____________.
Since oxygen has a ______________ electronegativity than hydrogen, oxygen holds onto shared
electrons ____________, giving the oxygen a __________ negative charge and the hydrogen a
partial _____________ charge.
2
CHEMISTRY: A Study of Matter© 2004, GPB, 5.1
32
polar covalent bonds:
• electrons are shared _________________, creating partially charged ends or _______.
nonpolar covalent bonds:
• electrons are shared ________________ because atoms have the same electronegativities
Electonegativity difference:
Greater than or equal to 1.7
Between 1.7 and 0.3
Less than or equal to 0.3
Examples:
Type of Bond
Mg and F?
S and O?
Program 501, problem set 1: What type of bond will form between . . .
Li and Cl?
C and O?
Na and Cl?
Cl and Br?
S and H?
Al and Al
metallic bond – occurs between metal elements; electrons are ________________ (creates a
“____ of ___________”)
Properties of metals:
1. _______________________________________________________________
2._______________________________________________________________
3._______________________________________________________________
4._______________________________________________________________
Summary
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
_________________________________________________________________
The Chemistry Quiz
CR1._____ CR2._____ 1._____ 2._____ 3._____ 4._____ 5._____
33
Identify the type of element whether metal, metalloid, and non-metal and whether it will form
a cation, anion, or if an ionic form is usually not present and draw its atomic Lewis dot
structure.
O non-metal, forms an anion (O-2)
N
H
F
Xe
Ca
S
Mg
Identify the type of elements that form the following bond types
Ionic_______________________________________________
Covalent ____________________________________________
Metallic_____________________________________________
Identify the type of covalent or ionic bond present between the following elements and draw
their Lewis Dot Structures
1. O2
2. NH3
3. F2
4. N2
5. H2O
6. Cl2
7. CaCl2
34
http://www.chem.wisc.edu/areas/reich/handouts/electronegativities.gif
INTERPRETING GRAPHICS - Bond Characteristics
35
Worksheet: Introduction to Bonding3
For each of the following statements, write ionic, covalent or metallic bonds.
______________ electrons are shared
______________ electrons delocalized
______________ electrons are transferred
______________ crystal lattice
______________ luster
______________ nonconductors in the solid, molten, and dissolved state
______________ malleable and ductile
______________ high melting and boiling points
______________ volatile liquids and gases
______________ weaker forces between atoms
______________ hard—difficult to crush
What is the difference between a cation and an anion?
In a polar covalent bond, the electrons are shared ____________. In a nonpolar covalent
bond, the electrons are shared ____________.
Predict what type of bond will form between the following pairs of atoms by element type
(metal, metalloid, nonmetal)
F and F
Na and O
Cl and Cl
Ti and O
Fe and Fe
Mg and O
O and H
Ca and S
Ag and Ag
Be and Cl
Ca and Cl
C and O
3
5.5
Modified 10/5/11 by MElizabeth
CHEMISTRY: A Study of Matter, © 2004, GPB,
36
Common Core Practice
Carbon forms covalent bonds with many different elements.
a.
Describe the difference between a nonpolar covalent bond and a polar covalent bond.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
b. Using electronegativity trends in the periodic table, rank the three covalent bonds shown below in order from least
polar to most polar. Explain your reasoning.
C–N
C–C
C–O
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
c.
Identify one covalent bond from part (b) in which the carbon atom has a partial positive charge. Explain your
answer.
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
37
If the attractive forces among solid particles are less than the attractive forces between the solid
and a liquid, the solid will
A probably form a new precipitate as its crystal lattice is broken and re-formed.
B be unaffected because attractive forces within the crystal lattice are too strong for the dissolution to occur.
C begin the process of melting to form a liquid.
D dissolve as particles are pulled away from the crystal lattice by the liquid molecules.
INTERMOLECULAR FORCES
38
WISC ONLINE Intermolecular Forces
2d. Students know the atoms and molecules in liquids move in a random pattern relative to one another
because the intermolecular forces are too weak to hold the atoms or molecules in a solid form
The term intramolecular force refers to bonding between atoms in compounds: ionic, covalent, and metallic
bonds
The term intermolecular forces refers to attractions between compounds such as hydrogen bonds (strongest)
dipole-dipole, and London forces (weakest) which are easily broken and formed.
In any substance at any temperature, the forces
holding the material together are opposed by the
internal energy of particle motion, which tends to
break the substance apart.
Intermolecular forces are the forces of attractions that
exist between molecules in a compound. These cause
the compound to exist in a certain state of matter:
solid, liquid, or gas; and affect the melting and boiling
points of compounds as well as the solubilities of one
substance in another.4
Solid: A state of matter in which the matter is not compressible nor does it flow.
Liquid: A state of matter in which the matter is not compressible but can flow.
Gas: A state of matter in which the matter is compressible and can flow.
The melting point of a compound is the temperature at which a compound turns from a solid to a liquid or a
liquid to a solid.
The boiling point of a compound is the temperature at which a compound turns from a liquid to a gas or a gas to
a liquid. This temperature is a true measure of the forces of attractions between molecules as molecules separate
from one another when they turn from a liquid to a gas.
The stronger the attractions between particles (molecules or ions), the more difficult it will be to separate the
particles. When substances melt, the particles are still close to one another but the forces of attraction that held the
particles rigidly together in the solid state have been sufficiently overcome to allow the particles to move. When
substances boil, the particles are completely separated from one another and the attractions between molecules are
completely overcome. The energy required to cause substances to melt and to boil, and thus disrupt the forces of
attraction, comes from the environment surrounding the material. If you place a piece of ice in your hand, the ice
will melt more quickly than if it is placed on a cold counter top. The energy required to melt the ice comes from
your hand, your hand gets colder and the ice gets warmer.
Intermolecular Forces – increase as molar mass increases
Ionic Compounds and Metals
Electrostatic forces - these forces occur between charged species and are responsible for the extremely high
melting and boiling points of ionic compounds and metals.
Covalent Compounds
London forces - all molecules have the capability to form London dispersion forces. These are solely dependent
on the surface area and the polarizability of the surface of the molecule. These are the only types of forces that
non-polar covalent molecules can form. They result from the movement of the electrons in the molecule which
generates temporary positive and negative regions in the molecule.
Dipole-dipole forces - only polar covalent molecules have the ability to form dipole-dipole attractions between
molecules. Polar covalent molecules act as little magnets, they have positive ends and negative ends which attract
each other.
Hydrogen bonding - these occur between polar covalent molecules that possess a hydrogen bonded to an
extremely electronegative element, specifically - N, O, and F.
4
http://cosm.georgiasouthern.edu/chemistry/general/molecule/forces.htm
39
Vocabulary and Basic Concepts and Properties
Metallic
Neutral
Nucleus Protons Zero Electronegativity
Covalent
Crystal lattice
Force
Ionic
Lowest Ionization
Charge
Malleable
Conductivity
substances
1. A chemical bond in an attractive _______________________ that holds atoms together.
2. Chemical bonding is the process of atoms combining to form new __________________________.
3. Matter tends to exist in its ______________________________ energy state.
4. A(n) __________________________ bond is a bond in which one atom transfers electrons to another atom.
5. When the number of protons equals the number of electrons an atom has a _________________________ charge.
6. Ions are atoms with a positive or negative _______________________________.
7. _______________________________ is the process of removing electrons from atoms to form ions.
8. _________________________________ is the tendency of an atom to pull electrons in bonds.
9. A bond in which atoms locally share electrons is called a _________________________ bond.
10. In a(n) ____________________________ bond many electrons are shared by many atoms.
11. Metallic bonds are _____________________________ thus metals are able to be pounded into many shapes.
12. Ionic compounds have a low _____________________________ in the solid state, and a higher
_________________________(same word) in the molten state or aqueous state.
Indicate whether the following statements are true (T) or false (F). If the statement is false, re-write the statement
to make it true.
1. Chemical bonding is the process of atoms combining to form new substances.
2. Valence electrons are in the innermost energy level.
3. Matter in its lowest energy state tends to be more stable.
4. Particles with a positive or negative charge are called ions.
5. One property common to metals is ductility.
6. Covalent molecules tend to have higher melting and boiling points compared to ionic compounds.
7. Covalent molecules conduct electricity in all states.
8. Hydrogen bonding intermolecular forces are stronger than London Dispersion intermolecular forces.
9. Ionic compounds typically exist in the gaseous phase at room temperature.
10. When an atom loses one or more electrons it becomes negatively charged and we call it a cation.
40
Ionic Compounds Review
Vocabulary Review
Terms to Match
Anion
Law of Multiple Proportions
Ionic Compounds
Binary Compounds
Cation
Law of Definite Proportions
Polyatomic Ion
Monoatomic Ion
____________________________Any atom or group of atoms that has a positive charge
____________________________Compounds composed of metal cations and nonmetal anions
____________________________Composed of two elements and can be either ionic or molecular
____________________________An ion consisting of a single atom with a positive or negative
charge
____________________________Whenever two elements form more than one compound, the
different amasses of one element that combine with the same
mass of the other element are in a ratio of small whole numbers
____________________________A tightly bound group of atoms that behaves as a unit and carries
a charge
____________________________In samples of any chemical compound, the masses of the elements
are always in the same proportions.
____________________________ any atom or group of atoms that has a negative charge.
Explain why ionic and metallic compounds have higher melting and boiling points than covalent
compounds
______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
41
Naming Mixed Ionic and Covalent Compounds
Name the following compounds. Remember, they may be either ionic or covalent compounds, so
make sure you use the right naming method!
1)
NaF __________________________________________
2)
NF3 __________________________________________
3)
Li2O __________________________________________
4)
Al2S3 __________________________________________
5)
MgSO4 __________________________________________
6)
SiH4 __________________________________________
7)
KNO3 __________________________________________
8)
P2O5 __________________________________________
9)
CH4 __________________________________________
10)
Ca(OH)2 __________________________________________
Write the formulas for the following compounds. Remember, they may be either ionic or covalent
compounds, so make sure you use the right method!
11)
lithium chloride __________________________________________
12)
nitrogen trichloride __________________________________________
13)
sodium oxide __________________________________________
14)
dinitrogen trioxide __________________________________________
15)
ammonia __________________________________________
16)
diboron dihydride __________________________________________
17)
potassium phosphide _________________________________________
18)
oxygen difluoride __________________________________________
19)
magnesium nitrate __________________________________________
20)
aluminum carbonate __________________________________________
42
CHEMICAL BONDING AND ATOMIC STRUCTURE VIDEO NOTES
Learning Objectives







Visualize chemical bonds as electrostatic forces between atoms
Compare behavior of valence electrons in metallic and covalent bondings
Recognize that the making and breaking of bonds involves energy changes
Compare the structure of atomic, ionic, and molecular crystals
Use types of bonding to account for physical and chemical properties
Appreciate the importance of the bonding capacity of carbon
Use electronegativity to account for trends in bonding in the periodic table
Before Viewing
1. What are the laws of electrostatics as applied to charged bodies.
2. What are valence electrons?
After Viewing
1. Explain why a football field was used to describe the relative size of an atom?
2. What are the three kinds of bonds?
3. What common properties of Fe and Cu can be explained by the metallic bond?
4. How can you account for differences in the conductivity of iron and copper?
5. What kind of bond would you expect between atoms of two different metals? Explain
6. What kind of bond would you expect between two different non-metals? Explain
7. Explain how the bonds transmit electricity and heat differently.
8. What does molten mean?
9. What does sublimation mean (it happens to iodine crystals)
10. In what ways can atoms of elements achieve the configuration of noble gases?
11. Use atomic structures to account for the increase in electronegativity across a period; its decrease from
the top to bottom of a group.
43
DEVELOPING A HYPOTHESIS
Suppose you and your neighbor are growing tomatoes. One day you notice that your neighbor's plants are much
bigger than yours. What's causing the difference? How can you get your plants to grow as big as your
neighbor's?
The question you asked about the tomato plants could lead you to develop a hypothesis. A hypothesis (plural:
hypotheses) is a prediction about the outcome of a scientific investigation. Like all predictions, hypotheses are
based on a person's observations and previous knowledge or experience.
In science hypotheses must be testable. That means that researches should be able to carry out an investigation
and obtain evidence that shows whether the hypothesis is true or false. The way a hypothesis is written can
outline a way to test it. Try to word each of your hypotheses in the form of an If... then… statement.
Read the following three examples. Notice which of these predictions are testable. Notice which are properly
worded hypothesis.
Example1: If I give my plants fertilizer, then they will grow as big as my neighbor's plants. (testable and
properly worded)
Example 2: If I get lucky, then my plants will grow bigger. (not testable, because you can't control getting lucky)
Example 3: My plants aren’t growing bigger because I don’t water them enough. (not worded properly)
TIPS for Developing Hypotheses
 Ideas for hypotheses often result from problems that have been identified or questions that have been
raised. To help develop ideas for a hypothesis, write down several questions about the topic. Try to
narrow the questions to one that can be investigated scientifically. Then write the hypothesis.
 Make sure the hypothesis is a prediction.
 Make sure the hypothesis can e tested through an investigation.
 Check the way you worded the hypothesis a properly worded hypothesis should take the form of an If…
then… statement.
Write a properly worded hypothesis based on this question: "Will empty trucks use the same amount of gas as
heavily loaded trucks? "
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
The day after a picnic, you look into the cooler. All of yesterday's
ice has turned into water. Only two beverages are left. A can of diet
soda is floating at the surface. A can of regular soda is resting at the
bottom. You pick up the two cans. You see that both drinks are
made by the same company. Then you read the labels.
Carbonated
Water
High
Fructose
Corn Syrup
Carmel
coloring
Artificial and
Natural
flavoring
44
Carbonated
Water
Aspartame
Carmel
coloring
Artificial and
Natural
flavoring
1. You think that something about the regular drink must have made it sink, while something about the diet drink
made it float. Write down at least two possible explanations for the event.
____________________________________________________________________________
____________________________________________________________________________
2. Suppose that the type of drink did not affect which can floated or sank. Maybe the cans themselves were different
in some way. Maybe something besides soda got into one of the cans by mistake. Write down at least two possible
explanations for the event.
____________________________________________________________________________
____________________________________________________________________________
3. Write down any other possible explanations that you can think of. Could the cooler have had any affect? Could
something in the water be responsible? Could there be an object in the water than you can't see?
____________________________________________________________________________
____________________________________________________________________________
4. Review you answers to Question 1. Use one of your ideas to write a hypothesis explaining why one can floated and
other sank. Hint: Make sure you use the words If… then…
____________________________________________________________________________
____________________________________________________________________________
5. Review your answers to Question 2 and 3. Choose one of your statements describing something besides the type of
drink that cased the floating or sinking. Write a hypothesis based on that idea.
____________________________________________________________________________
____________________________________________________________________________
6. Are both your hypotheses testable? Write a brief description of how you could test each one. Mention any
equipment you would need. You can open the cans and pour out the drinks as part of your tests
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
Review your work. Use it to help you write a short summary of how to develop a hypothesis about an event.
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
45
PRACTICE TEST
1. During a flame test, ions of a specific metal are heated in the flame of a gas burner. A characteristic color of light is
emitted by these ions in the flame when the electrons
a) gain energy as they return to lower energy levels
b) gain energy as they move to higher energy levels
c) emit energy as they return to lower energy levels
d) emit energy as they move to higher energy Levels
2. The high electrical conductivity of metals is primarily due to
a) high ionization energies
b) filled energy levels
c) mobile electrons
d) high electronegativity’s
3. Which statement best describes the density of an atom’s nucleus?
a) The nucleus occupies most of the atom’s volume but contains little of its mass.
b) The nucleus occupies very little of the atom’s volume and contains little of its mass.
c) The nucleus occupies most of the atom’s volume and contains most of its mass.
d) The nucleus occupies very little of the atom’s volume but contains most of its mass.
4. Which Group of the Periodic Table contains atoms with a stable outer electron configuration?
a) 1
b) 16
c) 8
d) 18
5. An atom of carbon-12 and an atom of carbon-14 differ in
a) atomic number
b) mass number
c) nuclear charge
d) number of electrons
6. Which list of elements contains two metalloids?
a) Si, Ge, Po, Pb
b) Si, P, S, Cl
c) As, Bi, Br, Kr
d) Po, Al, I, Xe
7. Which is the negatively charged particle located outside the nucleus of an atom?
(1)
electron
(2)
neutron
(3)
silicon
(4)
Which of the atoms pictured is not likely to form an ion?
(1) C
(2) Na
(3) O
(4) they are all equally likely to form an ion
proton
8. Which of the atoms pictured is likely to form an anion?
(1) C
(2) Na
(3) O
(4) they are all equally likely to form an ion
9. In the periodic table of the elements, elements in Group 1 have how many outer electrons?
(1) 0
(2) 1
(3) 4
(4) 8
10. As an Na atom forms an Na+ ion, the number of protons in its nucleus_________________. Explain.
A) remains the same
B) decreases
C) increases
46
11. Elements from which two groups in the periodic table would most likely combine with each other to form an ionic
compound?
A. 1 and 2
B.
1 and 17
C. 16 and 17
D. 17 and 18
12. The diagram below shows the structure of a brain chemical called acetylcholine:
Based on the nature of the elements making up acetylcholine, the bonds present in the compound are most likely…
A. nuclear
C. hydrogen
B. metallic
D. covalent
13. Which of the following elements can form an anion that contains 54 electrons, 74 neutrons, and 53 protons?
The illustration below shows two atoms of a fictitious element (M) forming a diatomic molecule.
14.
What type of bonding occurs between these two atoms?
A. covalent
B. ionic
C. nuclear
D. polar
15. When elements from group 1 (1A) combine with elements from group 17 (7A), they produce compounds. Which of
the following the correct combining ratio is between group 1 (1A) elements and group 17 (7A) elements?
A. 1:1
B. 1:2
C. 2:1
D. 3:2
16. The bonds in BaO are best described asA. covalent, because valence electrons are shared
B. covalent, because valence electrons are transferred
C. ionic, because valence electrons are shared
D. ionic, because valence electrons are transferred
17. The strength of an atom’s attraction for the electrons in a chemical bond is the atom’sA. electronegativity
C. heat of reaction
B. ionization energy
D. heat of formation
18. The chemical bond between which two atoms is most polar?
A. C–N
B. H–H
C. S–Cl
D. Si–O
19. When cations and anions join, they form what kind of chemical bond?
A. ionic
B. hydrogen
C. metallic
D. covalent
20. Which of the following atoms has six valence electrons?
A. magnesium (Mg)
B. silicon (Si)
C. sulfur (S)
D. argon (Ar)
21. Which change in state would involve a decrease in the intermolecular force of attraction holding the water
particles together?
A. H2O(l) → H2O(s)
B. H2O(g) → H2O(l)
C. H2O(g) → H2O(s)
D. H2O(s) → H2O(l)
47
22. This diagram represents a
a) neon atom
b) carbon atom
c) magnesium ion
d) magnesium atom
23. How many valence electron are illustrated?
a) 1
b) 7
c) 16
d) 17
24. How many unpaired electrons are present in a nitrogen atom?
a) 2
b) 3
c) 5
d) 7
Use the following Lewis diagram to answer questions 25 and 26
25. The Lewis diagram X:X represents
a) a nobel gas
b) an alkali metal
c) a diatomic molecule
d) an alkaline earth metal
26.Which of the following products could be formed from the two molecules represented above?
a) water
b) neon gas
c) carbon dioxide
d) hydrogen flouride
27. How many lone pairs and bonding pairs of electrons surround the central oxygen atom in the modified Lewis
diagram of water?
A.
B.
C.
D.
Lone Pairs
1
1
2
2
Bonding Pairs
1
2
1
2
28 Identify the name of the ionic compound Na2O.
a) sodium oxide
b) sodium (I) oxide
c) sodium (II) oxide
d) disodium monoxide
29. What is the name of the compound MnS2
a) manganese sulfide
b) manesium sulfide
c) manganese (II) sulfide
30. Which of the following is a monatomic gas at STP? A chlorine
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B fluorine
d) manganese (IV) sulfide
C helium
D nitrogen
31. How many atoms of each of the following elements are present in the compound copper (II) phosphate?
Copper
1
2
3
3
A.
B.
C.
D.
Phosphourous
1
1
2
2
Oxygen
4
4
0
8
32. Which is the name of the compound represented?
a) silicon bromide
b) silicon (II) bromide
c) silicon hexabromide
d) disilicon hexabromide
33. When cations and anions join, they form what kind of chemical bond?
A ionic
B hydrogen
C metallic
D covalent
34. Some of the molecules found in the human body are NHCHCOOH (glycine), CHO (glucose), and
CH3(CH2)16COOH (stearic acid). The bonds they form are
A nuclear.
B metallic.
C ionic.
D covalent.
35. The reason salt crystals, such as KCl, hold together so well is because the cations are strongly attracted to
A. neighboring cations.
B. the protons in the neighboring nucleus.
C. free electrons in the crystals.
D. neighboring anions.
36. What type of force holds ions together in salts such as CaF2 ?
A electrostatic
B magnetic
C gravitational
D nuclear
Name
Hydrogen
Chlorine
Ammonia
Molecular Formula
H2
Cl2
NH3
37. What type of bond do all of the molecules in the table above have in common?
A covalent
B ionic
C metallic
Methane
CH4
D polar
38. Why are enormous amounts of energy required to separate a nucleus into its component protons and neutrons even
though the protons in the nucleus repel each other?
A The force of the protons repelling each other is small compared to the attraction of the neutrons to each other.
B The electrostatic forces acting between other atoms lowers the force of repulsion of the protons.
C The interactions between neutrons and electrons neutralize the repulsive forces between the protons.
D The forces holding the nucleus together are much stronger than the repulsion between the protons.
39. What is the chemical formula for dinitrogen pentoxide?
a) NO
b) N2O5
c)N5O2
d) (N2O)5
40. Which of the following compounds is inorganic
a) NO2
b)C3H8
c) C6H12O6
d) CH3COOH
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Bell Ringers
10/7/13 – Solve the following conversion problems Show all work
Convert 0.25 moles K to atoms K
Convert 70.9 g Cl2 to mol Cl2
10/8/13 – Select the elements in order of increasing atomic radius.
Arrange He, K, Fr in order of decreasing atomic radius, then select the correct answer
a.
b.
He, K, Fr
K, Fr, He
c.
d.
Fr, K, He
Fr, He, K
.
Describe the periodic trend for atomic radius (refer to group trends and period trends)
____________________________________________________________________________
____________________________________________________________________________
10/9/13 - Solve the following conversion problems Show all work
303.9 kPa to atm
190Torr to atm
Human body temperature is 37° Celsius. What temperature does this correspond to on the Kelvin scale?
10/10/13 – Complete the table below:
Name
Electron
Symbol
Electric Charge
Location in the Atom
n
+1
Compare and contrast the nucleus and electron cloud in terms of mass and volume
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
10/11/13 What type of elements are in the following bonds
(a) Metallic
______________________________________________________________
(b) Ionic
______________________________________________________________
(c) Covalent _______________________________________________________________
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10/14/13 Calcium chloride is an ionic compound that is composed of calcium and chloride. Write the
formula and calculate the molar mass.
10/15/13
What is the name and formula of the ionic compound formed between Al and S
What is the molar mass of the compound?
How many moles are 37.5 g
10/16/13 Inventory elemental atoms and calculate molar mass of Iron (III) nitrate, Fe(NO3)3.
element
# atoms
mass
Total mass
10/17/13 Write the following isotopes using isotopic notation 𝐴
𝑍𝑋 .
C-14
K-39
Cl-35
U-238
Neutron
Electron
Alpha particle
Beta particle
Gamma ray
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10/18/13 – Which pair has identical electron configurations?
A) S and Ar
B) K and Na+
C) S2- and Ar
D) Cl- and K
Write three sentences explaining how you made your selection and how two different elements would
have the same configuration.
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
10/21/13
How do atoms achieve noble-gas electron configurations in single covalent bonds? Explain one example.
_____________________________________________________________________________
_____________________________________________________________________________
How do atoms achieve noble gas electron configurations in double covalent bonds? Explain one example.
_____________________________________________________________________________
_____________________________________________________________________________
How do atoms achieve noble gas electron configurations in double covalent bonds? Explain one example.
_____________________________________________________________________________
_____________________________________________________________________________
10/22/13 – What is the charge on an ionic compound, say for example KCl?
_____________________________________________________________________________
_____________________________________________________________________________
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10/23/13 – Draw Lewis Dot structures for the following molecules circling shared pairs and boxing lone
pairs of electrons
CH4
NH3
HCl
H2O
CO2
10/24/13 – Write the formula for the following compounds
Carbon tetrachloride
Magnesium Sulfate
Iron (II) Nitrate
Iron (III) Nitrate
Potassium sulfide
Dihydrogen dioxide
Magnesium Phosphide
Magnesium Phosphate
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1. Chemical compounds are formed when atoms are bonded together



Breaking a chemical bond is an endothermic process.
Forming a chemical bond is an exothermic process.
Compounds have less potential energy than the individual atoms they are formed from.
2. Two major categories of compounds are ionic and molecular (covalent) compounds.
3. Compounds can be differentiated by their chemical and physical properties.
 Ionic substances have high melting and boiling points, form crystals, dissolve in water (dissociation), and conduct electricity in
solution (aqueous) and as a liquid, not as a solid.
 Covalent or molecular substances have lower melting and boiling points, do not conduct electricity.
 Polar substances are dissolved only by another polar substance. Non-polar substances are dissolved only by other non-polar
substances.
 Metallic compounds have high melting and boiling points and conduct heat and electricity as a solid or liquid or aqueous.
4. Chemical bonds are formed when valence electrons are:
 Transferred from one atom to another – ionic.
 Shared between atoms – covalent.
 Mobile in a free moving “sea” of electrons – metallic.
5. In multiple (double or triple) covalent bonds more than 1 pair of electrons are shared between two atoms.
6. Polarity of a molecule can be determined by its shape and the distribution of the charge.
 Polar molecules must have polar covalent bonds.
 Polar molecules are asymmetrical.
 Nonpolar molecules are symmetrical and/or have no polar covalent bonds.
7. When an atom gains an electron, it becomes a negative ion, anion, and its radius increases.
8. When an atom loses an electron, it becomes a positive ion, cation, and its radius decreases.
9. Atoms gain a stable electron configuration by bonding with other atoms.
 Atoms are stable when they have a full valence level.
 Most atoms need 8 electrons to fill their valence level.
 H and He only need 2 electrons to fill their valence level.
 The noble gasses (group 18) have filled valence levels. They do not normally bond with other atoms.
10. Electron-dot diagrams (Lewis structures) represent the valence electrons in elements, compounds and ions.
 Electrons in Lewis structures are arranged by their orbitals.
 The first two electrons are placed together in the “s” orbital.
 The remaining electrons are spread among the 3 “p” orbitals.
 The “s” orbital must be filled first. Then each “p” orbital must have one electron before another “p” orbital gains a second.
 The filling of electrons in a dot diagram is accomplished by putting one dot on each of four sides before doubling up.
11. Electronegativity indicates how strongly an atom of an element attracts electrons in a chemical bond. These values are
based on an arbitrary scale. Electronegativity can also be described as electroaffinity.
12. The electronegativity difference between two bonded atoms can determine the type of bond and its polarity.
0.0 - 0.4 = non-polar covalent
0.4-1.7 = polar covalent
1.7+ = ionic
13. Bonding guidelines:
 Metals react with nonmetals to form ionic bonds, ionic compounds, formula units (salts).
 Nonmetals bond with nonmetals to form covalent compounds (molecules).
 Ionic compounds with polyatomic ions have both ionic and covalent bonds.
 Metals react with Metals to form metallic bonds
14. Intermolecular forces allow different particles to be attracted to each other to form solids and liquids.
 Hydrogen bonds are an example of a strong IMF between atoms.
 Hydrogen bonds exist between atoms of hydrogen and oxygen, fluorine, or nitrogen.
 Substances with hydrogen bonds tend to have much higher melting and boiling points than those without hydrogen bonds.
15. Physical properties of a substance can be explained in terms of chemical bonds and intermolecular forces. These include
conductivity, malleability, solubility, ductility, hardness, melting point and boiling point.
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Bonding
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Across
2. Electron _________ model - Proposes that all metal atoms in a metallic solid contribute their valence electrons to
form a "sea" of electrons; can explain properties of metallic solids.
7. A chemical reaction in which a greater amount of energy is required to break the existing bonds in the reactants than
is released when the new bonds form in the product molecules.
9. _________ bond - The force that holds two atoms together; may form by the attraction of a positive ion for a negative
ion or by the attraction of a positive nucleus for negative electrons (electrostatic).
10. _________ energy - The energy required to separate one mole of the ions of an ionic compound, which is directly
related to the size of the ions bonded and is also affected by the charge of the ions.
11. An ion that has a positive charge; forms when valence electrons are removed, giving the ion a stable electron
configuration.
12. __________ unit - The simplest ratio of ions represented in an ionic compound.
13. __________ covalent - A type of bond that forms when electrons are not shared equally.
14. An ion that has a negative charge; forms when valence electrons are added to the outer energy level, giving the ion
a stable electron configuration.
15. _________ structure - Uses an electron-dot diagram to show how electrons are arranged in molecules.
Down
1. __________ bond - The attraction of a metallic cation for delocalized electrons.
3. __________ bond - A chemical bond that results from the sharing of valence electrons.
4. Ionic __________ - The electrostatic force that holds oppositely charged particles together in an ionic compound.
5. A chemical reaction in which more energy is released than is required to break bonds in the initial reaction.
6. __________ electrons - The electrons involved in metallic bonding that are free to move easily from one atom to the
next throughout the metal and are not attached to a particular atom.
8. __________ ion - An ion formed from only one atom.
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