Write the formula for the ionic compound formed from magnesium and sulfur.

Write the formula for the ionic compound formed from magnesium and sulfur.

A) MgS B) MgS2 C) Mg2S D) MgS3 E) Mg3S2

Solution:

Writing Formula for Ionic Compounds

1. Separate your compound into two parts and write their formulas.

2. Identify the charges of the two parts. If you have a Roman numeral, that's the charge of the metal. Group 1= +1 Group 2 = +2 Group 16 = -2, Group 17= -1 Al= +3.

3. Cross multiply the numbers from the charges