Question

Rust forming on iron is an indication of which of the following?

A. atoms are being destroyed
B. A gas is forming
C. a chemical change is occurring
D. matter is being created

Answer 1

Answer;

C. a chemical change is occurring

Explanation;

• A chemical change is a type of change which involves formation of a new substance. Chemical change is also irreversible, that is once the change has occurred it is almost impossible to get the original substances back.
• In this case, formation of rust is an example of a chemical change. This occurs when rust is exposed to moisture and oxygen gas, to form hydrated iron (iii) oxide which is the chemical name for rust.

Answer 2

Answer: C. a chemical change is occurring

Explanation:

Chemical change is a change in which rearrangement of atoms take place and thus formation of new substances take place.

Corrosion of iron is called as rusting. Rusting is oxidation of iron in the presence of oxygen and water and leads to formation of hydrated ferric oxide $(Fe_2O_3.xH_2O)$.

$Fe+O_2+H_2O\rightarrow Fe_2O_3.xH_2O$