A gas barbecue burns propane gas to generate heat. Propane gas becomes carbon dioxide gas and water vapor as it burns. Oxygen from the air is a reactant in this process. This is an example of a chemical reaction.

Question

Why is burning propane gas a chemical reaction?

Responses

The atoms in propane and oxygen rearrange to form other substances after the reaction.
The atoms in propane and oxygen rearrange to form other substances after the reaction.

Oxygen is involved. Any process involving oxygen is a chemical reaction.
Oxygen is involved. Any process involving oxygen is a chemical reaction.

The water vapor that forms after the reaction is in the gas phase.
The water vapor that forms after the reaction is in the gas phase.

The atoms that make up propane and oxygen change into different atoms after the reaction.

Answer 1

The correct response is:

The atoms in propane and oxygen rearrange to form other substances after the reaction.

This response accurately describes why burning propane gas is a chemical reaction: during combustion, the atoms in the reactants (propane and oxygen) are rearranged to form new substances (carbon dioxide and water vapor), which involves breaking and forming chemical bonds. The other options do not correctly capture the essential nature of a chemical reaction, which is the transformation and rearrangement of atoms to create new products.