Question

evidence of a chemical reactions is anything that shows - a new substance has formed a change in the state of matter a solid dissolved in a liquid interaction between 2 gases

Explanation:

A chemical reaction is characterized by the formation of a new substance. A change in the state of matter (e.g., melting, boiling) is a physical change. A solid dissolving in a liquid (e.g., salt in water) is a physical process (solution formation). Interaction between two gases can be a physical mixing or a chemical reaction, but the key definite evidence of a chemical reaction is the formation of a new substance.

Answer:

a new substance has formed