Chemical Bonding
Introduction to
Chemical Bonding
Introduction to Chemical Bonding
Objectives:
1. Define chemical bond.
2. Explain why most atoms form chemical bonds.
3. Describe ionic and covalent bonding.
4. Explain why most chemical bonding is neither purely
covalent nor purely ionic.
5. Classify bonding type according to electronegativity
differences.
Chemical Bonds
What happens when two
atoms get close together?
What is a chemical bond?
• An electrical attraction
between nuclei and
valence electrons of
different atoms.
Atomic Bonding Song - YouTube
Chemical Bonding
F2
• Most atoms are found in
nature as part of
compounds.
• Atoms gain, lose, or
share electrons to
achieve lower potential
energy.
F - 1s22s22p5
Li - 1s22s1
LiF
Ionic and Covalent Bonding
Ionic Bonding
• Electrostatic attraction between cations and
anions
• Occurs as a result of the transfer of
electrons from one atom to another.
Covalent Bonding
• Electrostatic attraction resulting from
shared electron pairs between atoms.
Electronegativity Differences
Nonpolar covalent bond – bonding electrons are shared
equally
Polar Covalent bond – unequal sharing of bonded
electrons
Classifying Bonds
Bond
Electronegativity
Difference
S-H
2.5 – 2.1 =0.4
S-Cs
2.5 – 0.7 = 1.8
Ionic
S
2.8 - 2.5 = 0.3
Nonpolar
Covalent
Br
S-Br
More
Bond Type electronegative
element
Polar
covalent
S
Identify Bond Types
KF
Ionic
O2
Nonpolar covalent
ICl
Polar covalent
HBr
Polar covalent
NaF
Ionic
N2
Nonpolar covalent