Question

which one is not a sign of chemical change
gas release
melting ice cream
precipitation formation
odor

Explanation:

A chemical change results in a new substance being formed. Gas release, precipitation formation, and odor can be signs of new substances being created in a chemical reaction. Melting ice - cream is a physical change as it is just a change of state from solid to liquid without forming a new substance.

Answer:

melting ice cream