Atom

1. nucleus

1.1. protons

1.2. neutrons

2. elements

2.1. atomic mass

2.2. atomic number

2.3. periodic table

2.3.1. chemical family

2.3.2. period

2.3.3. electron configuration

2.3.3.1. diagonal rule

2.3.3.2. hunds rule

2.3.3.3. Pauli exclusion principle

2.4. atomic radius

3. electrons

3.1. electron cloud

3.2. valence electrons

3.3. no mass

3.4. charges

3.5. shells

3.5.1. orbitals

3.5.2. subshells

3.6. Aufbau principle

3.7. electron dot diagram

3.8. energy level

3.9. spin

4. Ion

5. isotope

6. radioactive

6.1. nuclear decay

6.1.1. alpha decay

6.1.1.1. alpha particles

6.1.2. beta decay

6.1.2.1. beta particles

6.1.3. gamma decay

6.1.4. positron emission

6.1.4.1. positron

7. subatomic particles