ICSE Class 8 Answered

The process of changing from one state to another state by the absorption or rejection of heat at a constant temperature is called change of state.Now change of state cycle is the series of changes that changes solid to liquid, liquid to vapor, vapor to again liquid and then changing liquid back to solid.For example, Ice after absorption of heat changes to water, water after absorbing more heat changes to steam, steam on lossing heat condensed and changes to water, this water upon freezing(removal of heat) turns intp ice.