1. Chemistry B11
Chapter 4
Chemical Bonds

2. Chemical Bonds Ionic bonds 2. Covalent bonds 3. Metallic bonds
4. Hydrogen bonds
5. Van der Waals forces

3. Chemical Bonds
Ionic bonds
2. Covalent bonds

4. Review Shell 1 Maximum 2 electrons in valence shell
Hydrogen and Helium
Main-group elements
1A – 8A
Other Shells
Maximum 8 electrons in valence shell

5. Na: 1s2 2s2 2p6 3s1 Na+: 1s2 2s2 2p6 Ne: 1s2 2s2 2p6
Octet rule
Noble gases
(Stable)
Goal of atoms
Filled valence shell
Na+: 1s2 2s2 2p6
+ e-
Na: 1s2 2s2 2p6 3s1
Ne: 1s2 2s2 2p6
Ar: 1s2 2s2 2p6 3s2 3p6

6. Na: 1s2 2s2 2p6 3s1 Na+: 1s2 2s2 2p6 Ne: 1s2 2s2 2p6
Octet rule
Noble gases
(Stable)
Goal of atoms
Filled valence shell
Na+: 1s2 2s2 2p6
+ e-
Na: 1s2 2s2 2p6 3s1
Ne: 1s2 2s2 2p6
+ e-
Cl: 1s2 2s2 2p6 3s2 3p5
Cl-: 1s2 2s2 2p6 3s2 3p6
Ar: 1s2 2s2 2p6 3s2 3p6

7. Mg: 1s2 2s2 2p6 3s2 Mg2+: 1s2 2s2 2p6 Ne: 1s2 2s2 2p6 Octet rule
Noble gases
(Stable)
Goal of atoms
Filled valence shell
+ 2e-
Mg: 1s2 2s2 2p6 3s2
Mg2+: 1s2 2s2 2p6
Ne: 1s2 2s2 2p6

8. Mg: 1s2 2s2 2p6 3s2 Mg2+: 1s2 2s2 2p6 Ne: 1s2 2s2 2p6 O: 1s2 2s2 2p4
Octet rule
Noble gases
(Stable)
Goal of atoms
Filled valence shell
+ 2e-
Mg: 1s2 2s2 2p6 3s2
Mg2+: 1s2 2s2 2p6
Ne: 1s2 2s2 2p6
+ 2e-
O: 1s2 2s2 2p4
O2-: 1s2 2s2 2p6
Ne: 1s2 2s2 2p6

9. Cation (Y+): Na+ Li+ Ca2+ Al3+
Metals: lose 1, 2 or 3 e-
Cation (Y+)
Ions
Nonmetals: gain 1, 2 or 3 e-
Anion (X-)
Number of protons and neutrons in the nucleus remains unchanged.
Cation (Y+): Na+ Li+ Ca2+ Al3+
Anion (X-): Cl- F- O2-

10. Transition elements 1A 2A 3A 4A 5A 6A 7A 8A

11. Two problems of Octet rule
1. The octet rule cannot be used for transition and inner transition elements.
Fe2+
Fe3+
Cu1+
Cu2+
2. Ions of period 1 and 2 elements with charges greater than +2 are unstable. C
C4+
C4- B
B3+
unstable
unstable

12. International Union of Pure and Applied Chemistry (IUPAC)
Naming Monatomic Cations
International Union of Pure and Applied Chemistry (IUPAC)
systematic names
Name of the metal + “ion”
H+ Hydrogen ion
Li+ Lithium ion
Ca2+ Calcium ion
Al3+ Aluminum ion
Cu1+ Copper(I) ion
Cu2+ Copper(II) ion
Fe2+ Iron(II) ion
Fe3+ Iron(III) ion
Hg+ Mercury(I) ion
Hg2+ Mercury(II) ion
Sn2+ Tin(II) ion
Sn4+ Tin(IV) ion

13. Naming Monatomic Cations
common name
“-ous” smaller charge
Name of the metal +
“-ic” larger charge
Cu1+ Copper(I) ion Cuprous ion
Cu2+ Copper(II) ion Cupric ion
Hg+ Mercury(I) ion Mercurous ion
Hg2+ Mercury(II) ion Mercuric ion
Fe2+ Iron(II) ion Ferrous ion
Fe3+ Iron(III) ion Ferric ion
Sn2+ Tin(II) ion Stannous ion
Sn4+ Tin(IV) ion Stannic ion

14. Naming Monatomic Anions
Stem part of the name + “-ide”
Anion
Stem name
Anion name F-
fluor
Fluoride ion
Cl-
chlor
Chloride ion
Br-
brom
Bromide ion I-
iod
Iodide ion
O2- ox
Oxide ion
S2-
sulf
Sulfide ion
P3-
phosph
Phosphide ion
N3-
nitr
Nitride ion

15. Naming Polyatomic Ions
Cation: NH4+ Ammonium
MnO4- Permanganate
CrO42- Chromate
Cr2O72- Dichromate
CO32- Carbonate
HCO3- Hydrogen Carbonate
(bicarbonate)
PO33- Phosphite
PO43- Phosphate
HPO42- Hydrogen phosphate
H2PO4- Dihydrogen phosphate
Anion:
OH- Hydroxide
NO2- Nitrite
NO3- Nitrate
SO32- Sulfite
SO42- Sulfate
HSO3- Hydrogen Sulfite
(bisulfite)
HSO4- Hydrogen sulfate
(bisulfate)

16. Ionic bonds Metal-Nonmetal Cl: 1s2 2s2 2p6 3s2 3p5 Na: 1s2 2s2 2p6 3s1
Anion
Cation
Na+: 1s2 2s2 2p6
Cl-: 1s2 2s2 2p6 3s2 3p6
Donating receiving e-

17. Sodium (Na)
NaCl
Chlorine (Cl)

18. matter are neutral (uncharged):
total number of positive charges = total number of negative charges
Na+
Cl-
NaCl
Ca2+
Cl-
CaCl2
Al3+
S2-
Al2S3
Ba2+
O2-
Ba2O2
BaO
Molecule of NaCl
Formula of NaCl

19. matter are neutral (uncharged):
total number of positive charges = total number of negative charges
Na+
NO3-
NaNO3
Ca2+
CO32-
Ca2(CO3) Ca(CO3)
Al3+
SO42-
Al2(SO4)3
Mg2+
NO2-
Mg(NO2)2

20. Naming Binary Ionic compounds
name of metal (cation) + name of anion
NaCl sodium chloride
CaO calcium oxide
Cu2O copper(I) oxide cuprous oxide
CuO copper(II) oxide cupric oxide
Naming Polyatomic Ionic compounds
BaCO3 barium carbonate
Li2SO4 lithium sulfate Li2SO3 lithium sulfite

21. Covalent bonds
Nonmetal-Nonmetal
Metalloid-Nonmetal
Sharing of
valence electrons

22. Lewis Dot Structure H He Li Al C N Cl H Or Cl
Lewis Structure
Cl: 1s2 2s2 2p6 3s2 3p5
H: 1s1
He: 1s2
Ar: 1s2 2s2 2p6 3s2 3p6

23. Unshared pair of electrons
(nonbonding pair of electrons) - (Lone pair) Cl H x
Shared pair of electrons
(bonding pair of electrons)
Only valance electrons are involved in bonding (ionic and covalent bonds).

24. Electronegativity Electronegativity Ionization energy
A measure of an atom’s attraction for the electrons
Electronegativity
Ionization energy

25. Covalent bonds
Nonpolar covalent bond: electrons are shared equally.
Polar covalent bond: electrons are shared unequally. H Cl δ+ δ-
Dipole

26. Electronegativity Difference Between Bonded Atoms
Electronegativity & bonds
Electronegativity Difference Between Bonded Atoms
Type of Bond
Less than 0.5
Nonpolar Covalent
0.5 to 1.9
Polar Covalent
Greater than 1.9
Ionic H H
2.1 – 2.1 = 0 Nonpolar covalent N H
3.0 – 2.1 = 0.9 polar covalent Na F
4.0 – 0.9 = 3.1 Ionic

27. Covalent compounds H H –
CH4
H C H
H – C – H – H H O O O O –
CH2O – –
H C H
H – C – H
H C H
H – C – H
Correct H H –
NH3
H N H
H – N – H

28. H H H H
H C C H
H C C H
C2H4 H H H H
C – C
C = C H H H H
Correct
H C C H
H C C H
C2H2
H – C – C – H
H – C C – H

29. of the second element + “ide”
Naming Binary Covalent compounds
Mono – Di – Tri – Tetra – Penta – Hexa – Hepta – Octa – Nona – Deca
Don’t use “mono” for the 1st element.
Drop the “a” when followed by a vowel.
prefix and full name of the first element in formula + prefix and the anion name
of the second element + “ide”
NO2 nitrogen dioxide
N2O4 dinitrogen tetr(a)oxide
CCl4 carbon tetrachloride
S2O3 disulfur trioxide

30. VSEPR: Valence-Shell Electron-Pair Repulsion method
VSEPR Model
VSEPR: Valence-Shell Electron-Pair Repulsion method
Bond angle: angle between two atoms bonded to a central atom.
Each region of electrons likes to be
as far away as possible from the others.

31. Bond Angles in covalent molecules
Linear molecules
2 regions
Trigonal planar
molecules
3 regions
Tetrahedral molecules
4 regions

32. Unshared electron paires
CH4
NH3
H2O

33. Molecule has polar bonds.
Polarity
Molecule has polar bonds.
Its centers of δ+ and δ- lie at different places (sides). H δ+ – δ- δ- δ+ δ+ δ+
H – C – H
O = C = O – δ- H δ+
nonpolar molecule δ- O δ- = N C H H δ+ H H δ+ H
polar molecule