Question

16 multiple choice 0.3 points of the following, only ________ is a chemical reaction. dropping a penny into a glass of water crushing of stone tarnishing of silver melting of lead dissolving sugar in water clear my selection

Explanation:

A chemical reaction results in the formation of new substances. Dropping a penny in water, crushing stone, melting lead, and dissolving sugar are physical changes. Tarnishing of silver is a chemical reaction as silver reacts with sulfur - containing compounds in the air to form silver sulfide, a new substance.

Answer:

C. tarnishing of silver