Question

7 rust forming when iron and oxygen mix is a sign of a chemical reaction. (a) a true b false (b) iron oxide is a a type of rust. rust is a solid. which image below represents how the molecules in iron oxide move?

Explanation:

(a) When iron reacts with oxygen (and water in the air), a new substance (rust, mainly iron oxide) is formed. This is a chemical reaction.
(b) In solids, molecules are closely packed and vibrate in fixed positions. Image A shows closely - packed molecules, which is characteristic of a solid.

Answer:

(a) A. True
(b) A. Image A (the one with closely - packed molecules)