Bonds and Electronegativity

There are 3 types of bonds:

Ionic.
Covalent.
Metallic.

Ionic bonds are when electrons are transfered from metal to non-metal. Covalent bonds are when electrons are transfered between non-metals. Metallic bonds are when pure metals are held together by electronegativity attraction.

electronegativity - (EN) is a measure of an atoms attractions for electrons in a bond

1. Atoms with a greater EN can attract more e- 
2. polar convalent bonds form from an unequal sharing
3. non-polar covalent bonds form from an equal sharing

Electronegativity has a specific rule for each elements.

• EN > 1.7 = ionic bond
• EN < 1.7 = polar covalent bond
• EN = 0 = non-polar convalent bond

Example:

1. Ba-I
   0.89-2.66
   1.77 = ionic bond
2. Co-P
   1.88-2.19
   0.31 = polar covalent bond
3. Hg-Po
   2.0-2.0
   0 = non-polar convalent bon