Question

2 substance that do not change the state of matter on heating​

Answer 1

Answer:

On heating a solid such as ice turns into water i.e liquid and that converts into water vapour/gas.

Gas/Vapours turn to liquid by contracting due to condensation, but on heating their physical state cannot reverse back into solid or liquid.

Hence, a gas on heating will remain a gas itself as it expands.

Furthermore, answer to your question is all gases like oxygen O2, carbon dioxide CO2, Hydrogen H2, etc.