C h e m i i c a l l B o n d i i n g
Name__________________________________Period:______Date:____________
1) __________________________= an interaction between atoms that holds them together by reducing the potential energy of their electrons
2) ____________________________= a shorthand representation of the composition of a substance using atomic symbols and numeric subscripts (Ex: NaCl,
MgCl
2
, H
2
O, C
12 6
H O
6
)
3) Chemical bonding involves the valence electrons of the atoms involved in a___________________________.
4) _____________________________= the electrons available to be lost, gained, or shared in the formation of chemical bonds
 For atoms of main group elements, valance electrons are electrons in the
_______________________ main energy level.
 Use of the periodic table to determine the number of valence electrons for atoms of the main group elements:
1
2
13
14
15
16
17
18
______________________= a helium atom has ________valence electrons
1

 Electron Configuration of oxygen:
5) In the Lewis electron-dot formulas for atoms of main group elements, valence electrons are represented by _________that surround an element’s symbol.
6) Examples of Lewis electron-dot formulas for atoms of the main group elements:
2

1)
= a chemical bond resulting from
________________________________between positive and negative ions a) In a purely ionic bond, one or more electrons are transferred from one atom to another
2) _______________________= a chemical bond resulting from the___________ of electrons between two atoms a) ___________________= a covalent bond in which the bonding electrons are ______________________ by the bonded atoms b) ______________________= a covalent bond in which the bonding electrons are ___________________ by the bonded atoms
3) Chemical bonds between two unlike atoms are NEVER completely ionic and RARELY completely covalent. Bonds
 +  can be anywhere in the range between these two extremes, depending upon how strongly the bonded atoms attract electrons.
-
3

4)
= a measure of the ability of an atom in a chemical compound to attract electrons
5) The degree to which bonds are ionic or covalent can be ___________________ by comparing the electronegativities of the bonded atoms.
6) The electronegativity difference of two atoms can be used to determine the ionic character of a bond.
 Only ___________________values are used for the final electronegativity
7) The scale below can be used to classify the probable bond type between two atoms. a) If the electronegativity difference between two atoms is:
 _________________the probable bond type is usually classified as___________________________.
 ______________________the probable bond type is usually classified as_______________________.
 _____________________the probable bond type is usually classified as
__________________.
8) Polar covalent bonds, a closer look: a) In a polar covalent bond electrons are________________________. b) Shared electrons spend MORE of their time near the atom with the
_____________________ electronegativity. c) __________________________ (  + or  ) result.
 A  - is assigned to the atom with the ________________electronegativity
 A  + is assigned to the atom with the ________________electronegativity d) Ex: An H atom and a Cl atom form a polar-covalent bond resulting in partial charges.
4

9) Determine the electronegativity difference and probable bond type with respect to bonds formed between the following pairs of atoms. Assign partial charges if the probable bond type is polar-covalent.
S and H
S and Cs
I and I
Cl and Br
S and Cl
Br and F
1) Characteristics of ionic compounds: a) Ionic compounds are held together by____________________________. b) Ionic compounds usually involve__________________________________. c) Ionic compounds are _____________under normal conditions. d) Ionic compounds consist of a very large number of positive and negative ions (anions and cations) that are combined so that the numbers of positive and negative charges are________________. e) The chemical formula for an ionic compound represents a formula unit, NOT a____________________________.
2) An ionic compound is __________composed of independent, neutral units that can be isolated and examined.
5

3) ____________________= a compound of positive and negative ions (anions and cations) that are combined so that the numbers of positive and negative charges are equal
4) The chemical formula of an ionic compound shows the _______of ions present in a sample of any size. a) Ex: magnesium chloride has the following chemical formula: MgCl
2
 For every one Mg +2 ion present, two Cl  ions are present.
 If 13 mol Mg +2 ions are present in a sample, then 26 mol Cl  ions are present in the sample.
5) The chemical formula for an ionic compound represents a formula unit, NOT a molecule.
6) __________________= the simplest collection of ions from which an ionic compound’s formula can be established
7) __________________= chemical compounds tend to form so that each atom (by gaining, losing, or sharing electrons) contains eight electrons in its outermost occupied main energy level (valence electrons)
8) Electron-dot formulas can be used to illustrate the formation of_________________. a) Use electron-dot formulas to illustrate the formation of ionic bonds involving Na and Cl.
Ionic Formula = ________________
6

b) Use electron-dot formulas to illustrate the formation of ionic bonds involving Ca and F.
Ionic Formula = ________________ c) Use electron-dot formulas to illustrate the formation of ionic bonds involving K and
O.
Ionic Formula = ________________
1) Characteristics of molecular substances: a) Molecular substances are held together by___________________________. b) Molecular substances usually involve ONLY ____________________. c) Molecular substances may be ______________________________under normal conditions. d) Molecular substances consist of_______________________. The_________ of different molecules varies greatly.
2) _______________________= a chemical compound whose simplest units are molecules
3) __________________= a neutral group of atoms held to together by
______________________________ a) A single molecule is an individual unit capable of existing on its own.
7

4) The chemical formula for a molecular compound is called a_________________.
5) _______________________________= a shorthand representation showing the types and numbers of atoms combined in a single molecule a) Ex: hydrogen peroxide; H
2
O
2
;________ atoms of hydrogen and _______ atoms of oxygen are held together by covalent bonds b) Ex: glucose; C
6
H
12
O
6
; 6 atoms of carbon, 12 atoms of hydrogen, and 6 atoms of oxygen are held together by __________________
6) _______________________= a molecule containing only two atoms a) Ex: HCl, O
2
7) Certain elements occur naturally as diatomic molecules (you need to know these
elements!!) a) They are: H
2
, O
2
, N
2
, Cl
2
, Br
2
, I
2,
and F
2
1) __________________________________________(IM Forces) = forces of attraction between adjacent particles (molecules, atoms, or ions) a) Generally much _________________ than ionic or covalent bonds b) The example below shows two HCl molecules. The force of attraction that exists between the two molecules is an intermolecular force. c) IM forces are ____________significant in solids and liquids than in gases because the particles are much closer together in solids and liquids. d) IM _______________are responsible for many properties of compounds such as melting point and boiling point, surface tension, and viscosity.
 Strong IM forces = ___________melting points & boiling points o Ex: ______________compounds o Requires_______________energy (higher temp.) to break strong IM forces between particles
 Weaker IM forces = __________melting points & boiling points
8

o Ex: ____________________compounds o Requires ________________energy (lower temp.) to break weak IM forces between particles
1) Lewis electron-dot formulas illustrate the sharing of ________________________ between atoms.
2) Electron pairs: a) _________________= an electron pair NOT involved in bonding b) ______________= an electron pair shared between two atoms
3) Types of covalent bonds: a) ________________________= a covalent bond produced by the sharing of one pair of electrons between two atoms
 Ex: H—H or H : H b) ________________________= a covalent bond produced by the sharing of two pairs of electrons between two atoms
 Ex: O
2
With six valence electrons each, two oxygen atoms can use twelve electrons to satisfy both octets. By sharing one electron from each oxygen, we can't have more than one oxygen's octet satisfied. We'll need to try a different sharing pattern; a double bond will work.
c) ____________________= a covalent bond produced by the sharing of three pairs of electrons between two atoms
 Ex: N
2
With five valence electrons each, two nitrogen atoms can use ten electrons to satisfy both octets. By sharing one electron from each nitrogen, we can't have either nitrogen's octet satisfied. We'll need to try a different sharing pattern; a triple bond will work.
9

d) In general, _________________are _________________and ____________than single bonds. e) In general, __________________are shorter and stronger than___________________.
4) Guide for Writing Lewis Electron-Dot Formulas for Molecules: a) Count the ___________number of valence electrons in the molecule. THESE
ARE ALL THE ELECTRONS YOU MAY USE! b) Identify the central atom and terminal atoms:
 H is always a terminal atom
 C, if present is usually the _____________atom
 Molecules tend to be somewhat symmetrical (if one atom is different than the others it is usually the central atom) c) Place _____________of electrons between each pair of bonded atoms to form a____________________. d) Add electron pairs around the _____________________to satisfy the octet rule for the terminal atoms. THERE ARE EXCEPTIONS TO THE OCTET RULE! (see
below) e) Assign left over electron pairs to the ___________________________. f) Orient atoms so there is _______________ electron pair repulsions around the central atom. (arrange electron pairs as far apart as you can) g) If the central atom has LESS than an octet of electrons, then move one or more lone pairs from the _________________atoms to form multiple bonds
(double and triple bonds).
 oxygen, nitrogen and carbon CAN form ___________________. h) DO THE FOLLOWING FINAL CHECKS:
 Check that the total number of valence electrons in the molecule is correct.
 Check that the octet rule is satisfied for all atoms. DON’T FORGET ABOUT
THE EXCEPTIONS.
5) EXCEPTIONS to the octet rule: a) _____________________is an exception to the octet rule. In a molecule, hydrogen contains ________electrons in its outermost occupied main energy level. HYDROGEN CAN FORM ONLY A SINGLE BOND AND WILL CONTAIN
NO LONE PAIRS!
10

b) ________________and _______________are SOMETIMES exceptions to the octet rule. These atoms sometimes contain less than eight electrons in their outermost occupied main energy level. Remembering that these atoms DO NOT
form double and triple bonds will be helpful when determining if they break the octet rule.
6) Guide for Writing Lewis Structural Formulas for Molecules and Polyatomic
Ions: a) Follow all guides from above except write a __________to indicate every bond pair. b) __________are still used to represent_________________.
7) Guide for Writing Lewis Electron-Dot Formulas for Polyatomic Ions: a) Follow the guide from above except:
 Add a ____________and _______________to the electron-dot and structural formulas
 Account for ______________when counting valence electrons
 A POSITIVE CHARGE indicates you have to _____________electron(s) o Ex: H
3
O +1 has ____ valence electrons:
 O= _______________
 H
3
= _____________
 So now there is _______ and you subtract ______since the ion has a _____charge to get the final total of ___ valence electrons o Ex: NH
4
+1
11

 A NEGATIVE CHARGE indicates you have to _________electron(s) o Ex: CO
3
-2 has _____valence electrons
 C= ________________________
 O
3
= ________________________
 So now there is ________and you add _____since the ion has a
_____charge to get the final total of _____valence electrons
1) The _____________________has proven useful in predicting molecular geometry and bond angles.
2) The VSEPR model assumes that atoms will orient themselves so as to ___________electron pair repulsions around the central atom.
3) Steps to determine molecular geometry and bond angles: a) Draw an electron-dot formula. b) Arrange the electron pairs around the central atom in a way that minimizes repulsion. In other words, put the electron pairs as far apart as possible. c) Determine molecular geometry: d) Predict the bond angles from the molecular geometry.
12

Molecular
Geometry
Atoms
Bonded to
Central
Atom
Lone
Pairs
Around the
Central
Atom
Predicted
Bond
Angles
2
3
3
2
2
4
0
0
1
1
2
0
SnCl
2
H
2
O
CH
4
BeF
2
BeF
3
NH
3
Example
13

e) Notice the bond angle distortion for molecules with a molecular geometry of
_____________________and ___________(with_____________________).
 Ex: O
3
is considered bent with a predicted bond angle of 120 º since there is only 1 lone pair of electrons
 Ex: H
2
O is considered bent with a predicted bond angle of 105  since there is
2 lone pairs of electrons
 VSEPR model assumes that _______________require more room than bond pairs and tend to compress the angles between bond pairs.
 In general, bond angles of at least _______________provide enough room for lone pairs that significant bond angle distortion does NOT occur.

 Easily shows molecular geometry
 A wooden peg represents a single bond (one bond pair of electrons)
 Use longer pegs first, then if needed use smaller pegs
 A spring represents a multiple bond
 A colored wooden ball represents various atoms
 When writing dot formulas and structural formulas you still will have to account for lone pair(s) of electrons since models do not account for lone pair(s)
P u r p l l e = i i o d i i n e o r f l l u o r i i n e
R
O e r d a n
= g e o x
= y g b r e n o m i i n e
L i i g h t t B l l u e = n i i t t r o g e n
B l l a c k = c a r b o n
G r e e n = c h l l o r i i n e
Y e l l l l o w = h y d r o g e n
14

Use the following chart to determine if a molecule is polar or
1.
Does the molecule have ANY polar covalent bonds?
NO
YES
2. Is the electronegativity of all terminal atoms the same?
The molecule is NONPOLAR
NO
The molecule is POLAR
YES
NO
3. Is the molecule “symmetrical”?
(Lone pairs on central atom means molecule is NOT symmetrical )
YES
Note: if the molecule only contains 2 atoms, stop after the first
question.
The molecule is POLAR
The molecule is NONPOLAR
15

Complete the following tables on pg 16-18 as a class.
16

17

18

1) Where are valance electrons located?______________________________
2) Why are valence electrons important?
3) Determine the number of valence electrons in one atom of each of the following elements. Then write the electron-dot notation for each element. a) Na b) F c) Rb d) Ba e) I f) Se g) Al h) C i) Mg j) He
19

1) When predicting probable bond types, list the ranges for the following: a.
Non-polar covalent =______________________________ b.
Polar-covalent = __________________________________ c.
Ionic = __________________________________________
2) Define ionic bond.
3) What is the difference between polar-covalent and non-polar covalent bond types?
4) A  is assigned to the atom with the (higher or lower) electronegativity.
5) Determine the electronegativity difference and probable bond type with respect to bonds formed between the following pairs of atoms. Assign partial charges if the probable bond type is polar-covalent.
Pair of
Atoms
H and H
Electronegativity Difference
Probable Bond
Type
Partial Charges (if polar-covalent)
S and O
H and I
K and Br
Si and Cl
H and F
Se and S
C and H
Na and Cl
O and H
N and N
I and Cl
20

1) Ionic compounds usually have what type of elements present?
2) Ionic compounds are ___________________________ under normal conditions.
3) Molecular compounds usually have what type of elements present?
4) Molecular compounds are ________________________under normal conditions.
5) Use electron-dot formulas to illustrate the formation of ionic bonds involving Li and Cl.
Ionic Formula = ________________
6) Use electron-dot formulas to illustrate the formation of ionic bonds involving
Ca and I.
Ionic Formula = ________________
7) Use electron-dot formulas to illustrate the formation of ionic bonds involving K and F.
Ionic Formula = ________________
8) Use electron-dot formulas to illustrate the formation of ionic bonds involving
Mg and Br.
Ionic Formula = ________________
21

9) Use electron-dot formulas to illustrate the formation of ionic bonds involving
Al and I.
Ionic Formula = ________________
10) Use electron-dot formulas to illustrate the formation of ionic bonds involving
Ca and O.
Ionic Formula = ________________
11) Use electron-dot formulas to illustrate the formation of ionic bonds involving
Na and S.
Ionic Formula = ________________
12) Use electron-dot formulas to illustrate the formation of ionic bonds involving
Al and S.
Ionic Formula = ________________
22

Complete the following table.
23

24

25

26

27

28

29

30

31

32

B o o n d i i n g B a s i i c c s W o o r r k s h e e e e t t
Vocabulary: Use your notes to help you identify the following vocabulary.
1) A __________________________________is a covalent bond produced by the sharing of two pairs of electrons
2) between two atoms
____________________________is a measure of the ability of an atom in a chemical compound to attract electrons
3) _________________________ is a chemical bond resulting from electrostatic attraction between positive & negative ions
4) A _________________ is a neutral group of atoms held to together by covalent bonds
5) __________________________ is a chemical bond resulting from the sharing of electrons between two atoms
6) A _____________________________ is a covalent bond produced by the sharing of three pairs of electrons between two atoms
7) ___________________________ is a covalent bond in which the bonding electrons are shared unequally by the bonded atoms
8) A _________________________is a molecule containing only two atoms
9) _______________________________ is an electron pair shared between two atoms
10) _____________________________________________ is an interaction between atoms that holds them together by reducing the potential energy of their electrons
11) __________________________________________________is the simplest collection of ions from which an ionic compound’s formula can be established
12) ___________________________________________is a shorthand representation of the composition of a substance using atomic symbols and numeric subscripts (Ex: NaCl, MgCl
2
, H
2
O, C
6
H
12
O
6
)
13) _________________________________________ is the tendency of compounds to form so that each atom
(by gaining, losing, or sharing electrons) contains eight electrons in its outermost occupied main energy level (valence electrons)
14) A __________________________________is a chemical compound whose simplest units are molecules
15) _____________________________ is the outermost electrons available to be lost, gained, or shared in the formation of chemical bonds
16) __________________________________________ is an electron pair NOT involved in bonding
17) ___________________________________ is a covalent bond in which the bonding electrons are shared equally by the bonded atoms
18) ____________________________________________ are forces of attraction between adjacent particles
(molecules, atoms, or ions)
33

Concepts: Answer the following questions.
1.
When predicting probable bond types, list the ranges for the following: d.
Non-polar covalent =______________________________ e.
Polar-covalent = __________________________________ f.
Ionic = __________________________________________
2.
Which atom is assigned the partial negative charge when a polar covalent bond is established?
3.
Ionic compounds contain what type of elements?_____________________________________
4.
What phase(s) of matter would you most likely find ionic compounds? _______________________
5.
Molecular substances usually involve only what type of elements? __________________________
6.
What phase(s) of matter would you most likely find molecular compounds? _____________________
7.
List the naturally occurring diatomic molecules.
________________________________________________________________
8.
In terms of IM forces, describe melting points and boiling points of ionic and molecular compounds?
9.
Use electron dot formulas to illustrate the formation of ionic bonds involving Li and N.
Ionic Formula = ________________
10.
Use electron dot formulas to illustrate the formation of ionic bonds involving Na and O.
Ionic Formula = ________________
34

Dot & Structural Formulas: For each of the following formulas determine the number of valence electrons and draw the electron dot formula and structural formula.
Formula
CO
Number of
Valence
Electrons
Lewis Electron Dot
Formula
Lewis Structural
Formula
SeF
2
NCl
3
BeCl
2
HCN
35

Dot & Structural Formulas: For each of the following formulas determine the number of valence electrons and draw the electron dot formula and structural formula.
Formula
PH
3
Number of
Valence
Electrons
Lewis Electron Dot
Formula
Lewis Structural
Formula
SO
3
CS
2
CH
2
O
SiCl
4
(silicon tetrachloride)
36

1) What are valance electrons? a.
Where are valance electrons found?
2) What is an ionic bond?
3) What is the difference between a non-polar covalent bond and a polar-covalent bond?
4) What is electronegativity?
5) When predicting probable bond types, list the ranges for the following: a.
Non-polar covalent =______________________________ b.
Polar-covalent = __________________________________ c.
Ionic = __________________________________________
6) Which atom is assigned the partial negative charge?
7) Ionic compounds contain what type of elements? _________________________________
8) What phase(s) of matter would you most likely find ionic compounds?___________________
9) What is the octet rule?
10) Molecular substances usually involve only what type of elements?__________________
11) What phase(s) of matter would you most likely find molecular compounds?
12) What are diatomic molecules? List the naturally occurring diatomic molecules.
37

13) What is the difference between lone pair electrons and bond pair electrons?
14) What are the exceptions to the octet rule when constructing electron dot formulas?
15) What needs to be added to the electron dot and structural formulas for polyatomic ions?
__________________________ & ______________________________
16) List the 6 types of molecular geometry that a compound may exhibit and the predicted bond angle.
17) Use electron dot formulas to illustrate the formation of ionic bonds involving Ca and Cl.
Ionic Formula = ________________
18) Use electron dot formulas to illustrate the formation of ionic bonds involving K and O.
Ionic Formula = ________________
19) What is the difference between the melting and boiling points of ionic and molecular compounds?
38

: Academic Chemistry A - Grade 11
Unit Essential Question(s):
Concept Concept Concept
Optional
Instructional Tools:
Guided Notes
Lab Materials:

Ionic vs. Molecular
Compound Lab

Modeling Lab
Concept
Chemical Bonds Bond Types Electron Dot and Structural
Formulas
VSEPR Model
Lesson Essential Questions: Lesson Essential Questions: Lesson Essential Questions: Lesson Essential Questions:
Why do chemical bonds How do you determine How can molecules and How can the VSEPR model form? probably bond type? polyatomic ions be represented using electron dot and structural formulas? be used to predict molecular geometry and bond angles?
Vocabulary: Vocabulary: Vocabulary:
Chemical bond
Chemical formula
Valence electrons
Ionic bonds
Covalent bond
Nonpolar-covalent bond
Polar-covalent bond
Electronegativity
Ionic compound
Formula unit
Octet rule
Molecular compound
Molecule
Molecular formula
Diatomic molecule
Intermolecular Forces
Vocabulary:
Lone pair electrons
Bond pair electrons
Single bond
Double bond
Triple bond
Central atom
Dot formula
Structural formula
VSEPR Model
Molecular geometry
Bond angles
Linear
Trigonal planar
Bent
Tetrahedral
Trigonal Pyramidal
Isomer
39

1) Chemical bond - an interaction between atoms that holds them together by reducing the potential energy of their electrons
2) Chemical formula - a shorthand representation of the composition of a substance using atomic symbols and numeric subscripts (Ex: NaCl, MgCl2, H2O, C6H12O6)
3) Valence electrons - the outermost electrons available to be lost, gained, or shared in the formation of chemical bonds
4) Ionic bonds - a chemical bond resulting from electrostatic attraction between positive & negative ions
5) Covalent bonds - a chemical bond resulting from the sharing of electrons between two atoms
6) Nonpolar-covalent bond - a covalent bond in which the bonding electrons are shared equally by the bonded atoms
7) Polar-covalent bond - a covalent bond in which the bonding electrons are shared unequally by the bonded atoms
8) Electronegativity - a measure of the ability of an atom in a chemical compound to attract electrons
9) Ionic compound - a compound of positive and negative ions (anions and cations) that are combined so that the numbers of positive and negative charges are equal
10) Formula unit the simplest collection of ions from which an ionic compound’s formula can be established
11) Octet rule - chemical compounds tend to form so that each atom (by gaining, losing, or sharing electrons) contains eight electrons in its outermost occupied main energy level (valence electrons)
12) Molecular compound - a chemical compound whose simplest units are molecules
13) Molecule - a neutral group of atoms held to together by covalent bonds
14) Molecular formula - a shorthand representation showing the types and numbers of atoms combined in a single molecule
15) Diatomic molecule - a molecule containing only two atoms (Natural = H
2
,O
2
, N
2
, Cl
2
, Br
2
, I
2
, F
2
)
16) Intermolecular forces (IM Forces) = forces of attraction between adjacent particles (molecules, atoms, or ions)
17) Lone pair electrons - an electron pair NOT involved in bonding
18) Bond pair electrons - an electron pair shared between two atoms
19) Single bond - a covalent bond produced by the sharing of one pair of electrons between two atoms
20) Double bond - a covalent bond produced by the sharing of two pairs of electrons between two atoms
21) Triple bonda covalent bond produced by the sharing of three pairs of electrons between two atoms
22) Central atom - atom in the center of the compound, often carbon
23) Dot formula - when dots are used to show bond pairs and lone pairs
24) VSEPR Model (Valence Shell Electron Pair Repulsion Model) has proven useful in predicting molecular geometry and bond angles
25) Molecular geometry Linear, Trigonal planer, Bent, Tetrahedral, Trigonal pyramidal, and Bent
26) Bond angles - angle at which the bond takes place
27) Linear - 2 atoms bonded to central angle and predicted bond angles is 180°
28) Trigonal planar - 3 atoms bonded to central angle and predicted bond angles is 120°
29) Bent -2 atoms bonded to central angle,1 lone pair around the central atom;predicted bond angle is 120°
30) Bent - 2 atoms bonded to central angle, 2 lone pairs around central atom; predicted bond angle is 105°
31) Tetrahedral - 4 atoms bonded to central angle; predicted bond angle is 109.5°
32) Trigonal Pyramidal - 3 atoms bonded to central angle, 1 lone pair around central atom; predicted bond angle is 107°
33) Isomer = Compounds that have the same molecular formula, but different structural formula.
40