Question: Which of the following substances can have variable composition?

Diamonds

Air

Graphite

Water

Answer: Air

Question: Which scientific law states the idea that elements combine in fixed ratios to form compounds?

Answer: law of constant composition

Question: T/F

Ionic Compounds are usually made up of a metal and a nonmetal

Answer: True

Question: Example of an ionic compound

Sodium chloride

Water

Carbon dioxide

Oxygen

Answer: Sodium Chloride