http://www.youtube.com/watch?v=OdQqFHNOWAA

• An isotope of chlorine has 17 protons and 19 neutrons. What is the mass number for that isotope of chlorine?
a. 2 b. 17 c. 19 d. 36

1. Binary ionic compounds (containing representative elements).
2. Binary covalent compounds (i.e. carbon dio x ide, carbon tetrachloride).

Why do atoms bond?

Naming Type 1- Ionic Compounds
Vocabulary
• Positive ion is called a “cation”
• Negative ion is call an “anion”
Rules
• Metal and non-metal
• The cation is always named first and the anion second.
• The cation takes the name of element
• The anion takes the first part of the element name (the root) then adds –ide.
• The net (overall) charge of a compound is always zero.
Example:
Sodium Chloride = Na +1 Cl -1

Naming Binary Ionic Compounds
Type 1 Ionic Compounds
• Metals (and H) that form only one cation
• Include H, Li, Na, K, Cs, Be, Mg, Ca, Ba, Al, Ag
• Name the following compounds:
Rb
2
O SrI
2
KS
2 rubidium oxide strontium iodide potassium sulfide

Naming Type 2 Binary Ionic Compounds
Ion
Fe 3+
Fe 2+
Cu 2+
Cu +
Rules
• These metals can form two or more cations
• Includes Cr, Cu, Fe, Sn, Pb, Co, Pb,
Hg
• http://quizlet.com/15999748/co mmon-simple-cations-anionscommon-type-ii-cations-flashcards/
• http://quizlet.com/15999748/tes t/?written=on&matching=on&mu lt_choice=on&tf=on&promptwith=1&limit=20
• Roman numeral specifies the charge of the ion
Systematic Name Older Name iron (III) iron (II) copper (II) copper (I) ferric ferrous
Cupric cuprous
Practice: Give the systematic name for each of the following:
• CuCl
• HgO
• Fe
2
O
3
• MnO
2
• PbCl
4 copper(I) chloride mercury(II) oxide iron(III) oxide manganese(IV) oxide lead(IV) chloride

Naming Type 3 Binary Compounds
Rules
• Type 3 contain ONLY
NONMETALS
• The first element is named by its element name
• The second element is named as though it is an anion with – ide
• The prefix mono is never used for naming the 1 st element.
The others prefixes can be used for the 1 st element.
Prefixes
• Mono 1
• Di 2
• Tri 3
• Tetra 4
• Penta
• Hexa
• Hepta
• Octa
5
6
7
8
Examples:
• BF
3
= boron trifluoride
• CO = carbon monoxide (not monocarbon monoxide)
• N
2
O = dinitrogen monoxide (common name nitric oxide is used by some dentists as an anesthetic)
• H
2
O= dihydrogen monoxide http://dhmo.org/

Practice Naming Binary Compounds http://quizlet.com/15999748/common-simplecations-anions-common-type-ii-cations-flashcards/ http://quizlet.com/15999748/test/?written=on
&matching=on&mult_choice=on&tf=on&promp t-with=1&limit=20

-In a chemical reaction, atoms are neither created nor destroyed.
-Chemical equations must be balanced or have the same number and kinds of atoms on the product side of the equation as the reactant side.

Writing Formulas for Compounds
• Each atom present is represented by its element symbol
• The number of each type of atom is indicated by a subscript written to the right of the element symbol
• When only one atom of a given type is present, the subscript 1 is not written
1. How many atoms of each element are in SO
3
?
sulfer-1; oxygen-3
2. How many atoms of each element when adding a coefficient such as 2S0
3
? sulfer-2; oxygen-6

• H
2
+ O
2
→ H
2
O
H= H=
O= O=
• H
2
O
2
→ H
2
O + O
2
• Na + O
2
→Na
2
O

• 2Mg
(s)
(s)
+ O
2(g)
→ 2MgO
• C
(s)
+ O
2(g)
→ CO
2(g)
• Ex: Hydrogen gas and oxygen gas burn to produce water.
• 2 H2 + O2 2 H2O and with sulfur trioxide reacts acid. water to make sulfuric
• H2O + SO3 H2SO4
• What would you see in a
"test tube" if you were witness to a synthesis reaction? You would see two different materials combine.
A single new material appears.

• Electrolysis of water is an example:
2 H
2
O → 2 H
2
+ O
2
• Another example is the decomposition of potassium chloride into potassium and chlorine gas:
2 KCl
(s)
→ 2 K
(s)
+ Cl
2(g)

• a more active element takes the place of another element in a compound and sets the less active one free.
• Replacement of a metal with a more active metal.
EX. Fe
(s)
+ CuSO
4(aq)
• Replacement of hydrogen in water by an active metal. EX. 2Na
(s)
→ FeSO
4(aq)
+ Cu
→ 2NaOH
(s)
(aq)
+ 2H
2
O
(l)
• EX. Mg
(s)
+ H
2 metals. EX. Zn
O
(g)
(s)
→ MgO
(s)
• Replacement of hydrogen in acids by active
+ 2HCl
(aq)
+ H
2(g)
→ ZnCl
2(aq)
+ H
2(g)
+ H
2(g)

1. Which one of the following physical states is not used for H
2
O in a chemical equation?
a. (s) b. (l) c. (aq) d. (g)
2. What type of chemical reaction is this?
Cl
2(g)
+ 2NaBr
(aq)
→ 2NaCl
(aq)
+ Br
2(l)
3. Mg
(s)
+ O
2(g)
MgO
(s)

The Periodic Table
Th ough there are some reversals in the trend (e.g., see
Po in the bottom row), atoms generally get smaller as you go across the periodic table and larger as you go down any one column.
Numbers are the radii in picometers
(pm).
Atomic Radii Trends

Increasing Ionization Energy

Electronegativity is a measure of the attraction of an atom for electrons in a covalent bond.
Fluorine, the most reactive non-metal, is assigned the highest value since it has the greatest attraction for the electron being shared by the other element. Oxygen is also highly electronegative and has a strong attraction for electrons.
Metals have low electronegativities since they have weak attraction for any shared electrons.
When two unlike atoms are convalently bonded, the shared electrons will be more strongly attracted to the atom of greater electronegativity. Such a bond is said to be polar . A polar bond results in the unequal sharing of the electrons in the bond.

Moving Left → Right
• Atomic Radius
Decreases
• Ionization Energy
Increases
• Electronegativity
Increases
Moving Top → Bottom
• Atomic Radius
Increases
• Ionization Energy
Decreases
• Electronegativity
Decreases

Covalent bonds are formed by diatomic and polyatomic molecules due to equal electronegativities.

1. Which combination of atoms can form a polar covalent bond?
a. H and H b. H and Br c. N and N d. Na and Br
The electronegativity difference between H (2.1) and Br (3.0) is 0.9. If the difference is less than 1.7 (but not zero, usually more than 0.4), a polar covalent bond is formed. A nonpolar covalent bond is formed when the difference is close to zero (usually up to 0.4). If the difference is more than 1.7, an ionic bond is formed.
2. A strontium atom differs from a strontium ion in that the atom has a greater a. # of electrons b. # of protons c. atomic # d. mass #
3. Which bond has the greatest ionic character (difference in electronegativity)?
a. H—Cl b. H—F c. H—0 d. H--N
H has an electronegativity of 2.1 and F has an electronegativity of 4.0. Subtract the two values and the difference is 1.9. Ionic bonds have differences of 1.7 or greater.