• 1. Protons and Neutrons– Atomic mass of the atom

• 2. Electrons – Orbitals and Energy Levels– Involved in Bonding

Energy Level (Electron Shell)

Orbitals Max Number of electrons

1 S 2

2 S and P 2; 6 = 8

3 S and P 2; 6 = 8

4 S, P and D 2; 6; 10 = 18

5 S, P and D 2; 6; 10 = 18

6 S, P, D and F 2; 6; 10; 14 = 32

Orbital

Maximum Electrons

S 2

P 6

D 10

F 14

• 1. Atoms ----------- Elements – Fe, Ag, Al, Na

• 2. Elements --------- Molecules and Compounds – Molecules vs Compounds