Question

What do these two changes have in common?

rust forming on a metal gate
an old sandwich rotting in a trashcan

A. Both are physical changes

B. Both are caused by heating

C. Both are chemical changes

D. Both are caused by cooling

Answer 1

Step-by-step explanation:

Neither of the changes are caused by heating or cooling, so options B and D can be eliminated.

Rust forming on a metal gate is a chemical change, while an old sandwich rotting in a trashcan is also a chemical change.

Therefore, the correct answer is C. Both rust forming on a metal gate and an old sandwich rotting in a trashcan are chemical changes.