As Mia mixed two substances in a test tube, she noticed that the test tube became warm. She also noticed gas coming from the test tube. Based on Mia's observations, what was most likely occurring inside the test tube?

This question lacks options. The options are:

A. The two substances underwent a physical change

B. The two substances were melting

C. A new substance was forming

D. A change in the mass of the two substances

The answer is C

Explanation:

Changes in chemistry can either be physical or chemical. A physical change as the name implies does not alter the chemical content of the susbtances involved. However, chemical changes affect the chemical composition of the substances, hence, new substances are produced.

A chemical change is also characterized with a color change, temperature change, gas evolution etc. In this question, Mia mixed two substances in a test tube and noticed that the test tube became warm, gas came out from the test tube. This implies a CHEMICAL CHANGE, LEADING TO THE FORMATION OF NEW SUBSTANCES.