Ionic Compound Formula Writing
A Grade 12 chemistry worksheet focusing on writing chemical formulas for ionic compounds, including those with polyatomic ions and transition metals.
Includes
Standards
Topics
Ionic Compound Formula Writing
Name:
Date:
Score:
Read each question carefully and write the correct chemical formula for the ionic compounds. Remember to balance charges and use parentheses for polyatomic ions when necessary.
Ionic compounds are formed when a metal and a nonmetal transfer electrons, creating oppositely charged ions that attract each other. This image illustrates the formation of an ionic bond.

Write the chemical formula for each of the following binary ionic compounds.
1. Sodium chloride:
2. Magnesium oxide:
3. Aluminum sulfide:
4. Potassium iodide:
Write the chemical formula for each of the following ionic compounds containing polyatomic ions.
1. Calcium hydroxide:
2. Ammonium phosphate:
3. Sodium sulfate:
4. Aluminum nitrate:
Write the chemical formula for each of the following ionic compounds with transition metals. Remember to consider the Roman numerals.
1. Iron(III) chloride:
2. Copper(II) oxide:
3. Lead(IV) sulfide:
4. Chromium(III) bromide:
1. Explain why parentheses are used when writing the formula for compounds with polyatomic ions, such as in Mg(OH)₂.
2. A student incorrectly wrote the formula for aluminum oxide as AlO. Identify the error and write the correct formula, explaining your reasoning.