Ionic Compounds and Their Properties

The video tutorial explains how to write the formula for copper(II) sulfide. It begins by identifying copper and sulfur on the periodic table, noting that copper is a metal and sulfur is a non-metal, forming an ionic compound. The tutorial discusses the charges of copper and sulfur, with copper having a 2+ charge and sulfur a 2- charge. These charges must balance to form a neutral compound, resulting in the formula CuS for copper(II) sulfide.

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 charge on a copper ion in copper(II) sulfide?

• 2-

• 2+

• 1+

• 1-

What is the charge on a sulfide ion?

• 1+

• 2+

• 1-

• 2-

Why must the charges in copper(II) sulfide add up to zero?

• To form a covalent bond

• To ensure the compound is stable

• To make the compound soluble

• To achieve a neutral compound

What is the correct formula for copper(II) sulfide?

• CuS2

• CuS

• Cu2S

• Cu2S2