1. Atomic Mass & Number Isotopes The Periodic Table

2. Atomic Number & Mass The atomic number of an element is determined by the number of protons found in the nucleus. The atomic mass of an element is the sum of the protons and neutrons in the nucleus. Atoms of an element have the same number of protons and electrons, resulting in a 0 charge.

3. Periodic Organization The periodic table is organized in order of increasing atomic number. Atoms that have the same number of protons but a different number of neutrons are called isotopes.

4. Elements & Isotopes The identity of an element is determined by the number of protons in the nucleus. Isotope symbols show the atomic mass and number for that element. carbon- 14 Isotope names show the written name and the mass only.

5. Periodic Grouping periods groups