This is known as a chemical change. The other kind of change in chemistry is a physical change, which is when a substance changes without becoming a new chemical. These physical changes are often ...

chemical changes happen when chemical reactions occur. They involve the formation of new chemical elements or compounds. Physical properties close physical propertyA property of an element or ...

So how do we know something is there? See for yourself. Heat Up to Some Cool Reactions All chemical reactions have one thing in common: temperature change. Learn the difference between chemical ...

and physical chemistry. They began to study areas such as: How living things get energy from food The chemical basis of heredity What fundamental changes occur in disease Biochemistry includes the ...