Question

which is an indicator of a chemical change? production of gas all of these a change in shape a reversible change

Explanation:

A chemical change results in the formation of new substances. Production of gas is an indicator as it shows new gaseous substances are formed. A change in shape is a physical change, and a reversible change is not a definite sign of a chemical change as physical changes can also be reversible.

Answer:

A. Production of gas