1. MgO has more lattice energy than NaF
the energy needed to completely separate an ionic solid into gaseous ions
proportional to ionic charges and inversely proportional to ionic radii.
MgO has more lattice energy than NaF
Mg2+ O Na+ F-
stronger bond
NaF has more lattice energy than KCl
smaller atoms larger atoms
Multiple Bonds
In many covalent bonding situations, multiple
chemical bonds exist — more than one pair of
electrons shared electron

2. In general, the more polar the bond, the stronger it is
Electronegativity and Bond Polarity
the difference in electronegativities between the two atoms bonded indicates the polarity of the bond
The more electroneagtive of the two atoms is always the atom that possesses the slightly negative charge
In general, the more polar the bond, the stronger it is

3. P = 5
Cl = 7
X 1 =
X 3 = +
This is your special number 26 .. .. Cl .. .. .. .. .. Cl .. P Cl .. ..
PCl3

4. H = 1
C = 4
X 1 =
N = 5
X 1 = +
X 1 =
This is your special number 10 .. .. H C N ..
HCN

5. Br = 7
O = 6
X 1 = 7
This is your special number
X 3 = + 25
+ 1 = 26
Ion has a negative 1 charge .. - .. O .. .. .. .. .. O Br O .. .. ..
BrO3-

6. Br = 7
O = 6
This is your special number
X 3 = 18 .. .. .. .. O O O .. .. .. .. .. .. .. O O O .. .. .. O3

7. C = 4
O = 6
X 1 = 4
This is your special number 2- .. O ..
X 3 = + .. .. .. .. O C O 22 ..
+ 2 = 24 ..
Ion has a negative 2 charge .. 2- .. .. 2- O .. .. O .. .. .. .. .. .. .. O C O .. .. .. O C O .. ..
CO32-

8. Cl = 7
O = 6
X 1 = 7
This is your special number
X 2 = +
That’s odd!! 19
double check your math .. .. .. .. .. O Cl O .. .. .
ClO2

9. .. .. .. .. . NO N O N = 5 O = 6 X 1 = 5 This is your special number+
That’s odd!! 11
double check your math .. .. .. N O .. . NO

10. N = 5
O = 6
X 1 = 5
This is your special number
X 2 = +
That’s odd!! 17
double check your math .. . .. .. .. O N O .. ..
NO2

11. Typically you’d rectify this with . . . . . .
B = 3
F = 7
X 1 =
X 3 = +
This is your special number 24 .. .. F .. .. .. .. .. F .. B F ..
Typically you’d rectify this with
a double bond
But
Double bonds won’t form with hydrogen or halogens
BF3

12. P = 5
Cl = 7
X 1 =
X 5 = +
This is your special number 40 .. .. .. Cl .. .. .. Cl .. Cl .. .. P .. .. .. .. Cl Cl .. ..
PCl5

13. S = 6
F = 7
X 1 =
X 4 = +
This is your special number 34 .. .. F .. .. .. .. .. .. F .. S F .. .. .. .. F
SF4

14. As = 5
F = 7
X 1 = 5
This is your special number
X 6 = + 47
+ 1 = 48
Ion has a negative 1 charge .. - .. .. .. F .. .. F .. .. F .. As .. .. .. .. .. F F .. .. F .. ..
AsF6-

15. I = 7
Cl = 7
X 1 =
This is your special number
X 4 = + 35
+ 1 = 36 .. .. - Cl .. .. .. .. .. .. .. Cl .. I Cl .. .. .. Cl ..
ICl4-

16. To expand the octet requires d-orbitals . . . . . . . .
There are no 1d or 2 d orbitals!