Smallest particle of an element

two or more atoms bonded together

a solid in which the atoms are arranged in a pattern that repeats again and again

A substance made of only one kind of matter and having definite properties.

A substance made up of atoms of two or more different elements joined by chemical bonds

A number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant and product are involved in a reaction

A number written slightly below and to the right of a chemical symbol that shows how many atoms of an element are in a compound.

Symbols that show the elements in a compound and the ratio of atoms