The smallest unit of ordinary matter that forms a chemical element

A negatively charged subatomic particle found outside of the nucleus of the atom

A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction

Physical combinations of two or more different substances that retain their own individual properties and are combined physically (mixed together)

A positive subatomic particle found in the nucleus of an atom

Pure substances that are composed of two or more types of elements that are chemically combined

Negatively charged particles found outside the nucleus and are equal to the number of protons.  They are involved in the formation of chemical bonds.

Smallest possible unit into which matter can be divided, while still maintaining its properties

Groups of two or more atoms held together by chemical bonds

The basic unit of a chemical element, consisting of a nucleus surrounded by electrons.