1. PROTON Proton: the positively charged particle found in the nucleus of an atom.

2. ELECTRON CLOUD

3. PERIOD Periods are the rows going across. They are numbered from 1-7 and indicate how many energy levels (shells/orbitals) the element has.

4. ATOM An atom is the basic unit of an element! Each atom has a nucleus surrounded by electrons.

5. PERIODIC TABLE

6. NEUTRON Neutrons are found in nucleus with protons. Neutrons have NO charge.

7. ELECTRON Electrons surround the nucleus of an atom in the electron cloud. Electrons have a (-) Negative charge!

8. ELEMENT

9. VALENCE ELECTRONS The electrons found in the outer most energy level/shell/orbital.

10. ISOTOPE Isotopes are elements that have more neutrons than the original element but still share the same chemical properties.

11. NUCLEUS The dense center of an atom. Where the protons and neutrons are located.

12. GROUP The columns on the periodic table. Groups indicate how many valence electrons each element in that column have.

13. ATOMIC MASS Protons (or atomic number) + Neutrons = Atomic Mass !