Ionic Compounds and Their Formulas

The video tutorial explains how to write the formula for calcium sulfide by using the periodic table to identify calcium as a metal and sulfur as a non-metal, forming an ionic compound. It discusses the importance of balancing the charges of calcium (2+) and sulfur (2-) to achieve a net charge of zero, resulting in the formula CaS. The tutorial concludes by cleaning up the formula for clarity.

What type of compound is formed when a metal and a non-metal combine?

• Molecular compound

• Metallic compound

• Ionic compound

• Covalent compound

What is the ionic charge of calcium when forming calcium sulfide?

• 1-

• 2-

• 1+

• 2+

What is the ionic charge of sulfur in calcium sulfide?

• 1-

• 2-

• 1+

• 2+

Why do the charges of calcium and sulfur need to add up to zero in calcium sulfide?

• To ensure the compound is stable

• To make the compound metallic

• To balance the equation

• To make the compound covalent

What is the final formula for calcium sulfide?

• Ca2S2

• CaS

• Ca2S

• CaS2