1. Please take your own notes.
Atomic Math
Please take your own notes.

2. # of Protons
Atomic number = number of protons 7

3. # of Electrons Atomic number = number of electrons 7
Note: This is true for ATOMS where the positives (protons) balance out the negatives (electrons).
This is NOT true for IONS which have extra charges…

4. Atomic Mass Atomic mass = # Protons + # Neutrons 7
Definition: Nucleon is a particle in the nucleus. Protons and neutrons are both “nucleons”
Note: Atomic mass = # of nucleons

5. Number of Neutrons Atomic mass = # Protons + # Neutrons
# Neutrons = Atomic Mass - Atomic Number 7

6. Na Different Notations Atomic Mass is always the larger number
Outside of the periodic table, you might see something like this:
Atomic Mass 23 Na 11
Atomic number
Atomic Mass is always the larger number

7. Where do electrons go? 1st Shell Holds up to 2 2nd Shell Holds up to 8
3rd Shell Holds up to 18
Rule: Fill from the inside out