Question

Which of the following is an example of chemical reaction?

• A. Conversion of steam to water
• B. Rusting of iron
• C. Cutting of wood
• D. All of the above

Answer 1

The correct option is B Rusting of iron

Rusting of iron is a chemical reaction. When iron rusts, it reacts with oxygen present in water or moisture in the air to create a new compound called iron (III) oxide.
$Fe\left(s\right)+O_2\left(g\right)\to F{e}_2{O}_3.x{H}_{2}O\left(s\right)$

$F{e}_2{O}_3.x{H}_{2}O$ is commonly known as rust and has properties entirely different from that of iron or oxygen.

Other options involve either change in physical state or size.