Mastering the Criss-Cross Method for Ionic Compounds

What is the first step in using the crisscross method for writing the formula of calcium nitride?

• Write the symbols for calcium and nitrogen

• Look up the charges of calcium and nitrogen

• Crisscross the charges

• Balance the charges

What is the final formula for calcium nitride using the crisscross method?

• Ca3N2

• Ca2N3

• CaN

• CaN2

What is the charge of calcium in calcium fluoride?

• 1-

• 3+

• 2+

• 1+

What is the final formula for calcium fluoride using the crisscross method?

• Ca2F3

• CaF2

• Ca2F

• CaF

What is the charge of the sulfate ion in calcium sulfate?

• 3-

• 2+

• 2-

• 1-

What is the final formula for calcium sulfate using the crisscross method?

• Ca2(SO4)3

• Ca2SO4

• CaSO4

• Ca(SO4)2

What is the charge of aluminum in aluminum sulfate?

• 2-

• 3+

• 2+

• 1+

What is the final formula for aluminum sulfate using the crisscross method?

• Al(SO4)2

• Al3(SO4)2

• Al2(SO4)3

• AlSO4

What is the charge of iron in Iron III oxide?

• 1+

• 2+

• 3+

• 2-

What is the final formula for Iron III oxide using the crisscross method?

• FeO3

• Fe3O2

• Fe2O3

• FeO