Question

If a metal changes color over time from exposure to air, what has likely occurred?

a) a chemical change

b) a reversible change

c) a change of state

d) a physical change

Answer 1

Option A. a chemical change

Step-by-step explanation:

A chemical change is a change in which new substance is formed and can not be easily reversed. A change of metal color when exposed to air for a long time is simply called rusting. This is a chemical change as new substance is formed. This can be seen when Zn roofing sheets changes color over time on exposure to air.