Question

1. rust has formed all over the metal key. the rust is a new substance resulting from the iron in the key reacting to oxygen and moisture in the air. is this an example of a chemical or physical change?

o physical
o chemical

Explanation:

A chemical change results in the formation of a new substance. Rust is a new substance formed when iron in the key reacts with oxygen and moisture in the air, which is a chemical reaction. In a physical change, no new substances are formed.

Answer:

chemical