Which of the following could provide definitive evidence of a chemical reaction? Choose two correct answers.(1 point)

Question

Responses

A new substance, rust, has formed.
A new substance, rust, has formed.

Liquid water has frozen to form ice.
Liquid water has frozen to form ice.

A solid has dissolved in a liquid.
A solid has dissolved in a liquid.

A new substance, oxygen gas, has formed.

Answer 1

The two responses that could provide definitive evidence of a chemical reaction are:

1. A new substance, rust, has formed.
2. A new substance, oxygen gas, has formed.

These indicate that a chemical change has occurred, resulting in the formation of new substances. In contrast, the freezing of water and the dissolving of a solid are physical changes, not chemical reactions.