There are two kinds of change. 1. Physical Change and 2. Chemical Change

Water and Ice are chemically the same substance.

 

Def: Physical change is a change in which no new substance is formed, but the original substance gains new properties.

 

There is no change in mass in a physical change; it is easy to reverse a physical change.

Def: A chemical change is a change in which at least one new substance is formed.

 

When a chemical change takes place we call what happens a chemical reaction.

 

Def: Law of conservation of matter: matter is neither created nor destroyed in a chemical reaction.