1. Introduction to Chemical Bonding

2. Introduction to Chemical Bonding
Objectives:
Define chemical bond.
Explain why most atoms form chemical bonds.
Describe ionic and covalent bonding.
Explain why most chemical bonding is neither purely covalent nor purely ionic.
Classify bonding type according to electronegativity differences.

3. 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

4. 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

5. 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.

8. Electronegativity Differences
Nonpolar covalent bond – bonding electrons are shared equally
Polar Covalent bond – unequal sharing of bonded electrons

9. Electronegativity Difference More electronegative element
Classifying Bonds
Bond
Electronegativity Difference
Bond Type
More electronegative element
S-H
2.5 – 2.1 =0.4
Polar covalent S
S-Cs
2.5 – 0.7 = 1.8
Ionic
S-Br
= 0.3
Nonpolar
Covalent Br

10. Identify Bond Types KF O2 ICl HBr NaF N2
Ionic Nonpolar covalent Polar covalent