2 what happens during a physical change new substance are formed the identity of the substance is change A chemical reaction occurs the form of a substance change but its identity.
3when enough heat is added to liquid water it boils and bubbles of water of water vapor rise to the surface and into the air.which type of change is this and why.
The first part under 2 makes no sense as stated.
For the part labeled 3, water boiling is a physical change since the liquid water is H2O and the boiling water vapor is H2O. No change in identity.