1. Types of Chemical Bonds

2. A chemical bond is
A link between atoms due to the mutual attraction of their nuclei for electrons

3. There are 3 major types of chemical bonds:
Ionic bond: typically between metals and nonmetals
Covalent bond: typically between 2 nonmetals
Metallic bond: between 2 metals

4. Ionic bond
Electrostatic attraction that binds positive and negative ions
In a purely ionic bond, one atom has given up one or more electrons to another atom

5. Ionic compound properties
poor conductors as solids, but good conductors as liquids
moderate to high melting points
soluble in polar solvents (like water)

6. Covalent bond
Results from the sharing of electrons between two atoms

7. Covalent compound properties
insoluble in most solvents
unable to conduct electricity
low melting points
at room temperature, are frequently liquid or gas
as a solid, hard and brittle

8. Two types of covalent bonds:
1.Nonpolar-covalent bond:
bonding electrons are shared equally by the bonded atoms; balanced distribution of electrical charge
2.Polar-covalent bond:
unequal attraction for the shared electrons

9. Classification of bonds according to differences in electronegativity (attraction for electrons)
> 1.7 ionic
polar covalent
nonpolar covalent

10. Example: What kind of bond will form between cesium and chlorine?
Determine electronegativities
Cl is 3.0 and Cs is 0.7
Subtract the lower electronegativity from the larger one
3.0 – 0.7 = 2.3
2.3 is > 1.7 then it is IONIC