A chemical change in which you start with one or more substance and end up with a new substance (or more) is a chemical reaction. The substances before the change are the reactants. The products or compounds are the new substances after the change. This worksheet let you understanding in the basic of compounds

What happens in a chemical reaction?

Introduction to learning in Chemistry by match the correct letter with the element name for junior high school student or primary science study.

The periodic table below has some of the symbols missing. Try to fill in the blank spaces.