1. Classifying the Elements

2. Squares in the Periodic Table
The periodic table displays the symbols and names of the elements, along with information about the structure of their atoms.
Symbols are either black for solid, red for gas, or blue for liquid.

3. Alkali Metals
Group 1A elements are called alkali metals – 1 valence electron.

4. Alkaline Earth Metals
Group 2A contain the alkaline earth metals – 2 valence electrons.

5. Boron Family
Group 3A is the Boron Family – 3 valence electrons.

6. Carbon Family
Group 4A – 4 valence electrons

7. Nitrogen Family
Group 5A is the Nitrogen Family. There are 5 valence electrons.

8. Oxygen Family
Group 6A – 6 valence electrons.

9. The Halogens
Groups 7A are the halogens – 7 valence electrons.

10. The Noble Gases
Group 8A are the most stable elements and do not have any valence electrons.

11. Electron Configurations in Groups
Elements can be sorted into noble gases, representative elements, transition metals, or inner transition metals based on their electron configurations.

13. Electron Configurations for Noble Gases
Helium
1s2
Neon
1s2 2s2 2p6
Argon
Krypton
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6

14. Electron Configurations for Representative Elements
Elements in groups 1A and 7A are referred to as representative elements because they display a wide range of physical and chemical properties.
In atoms of representative elements, the s and p sublevels of the highest occupied energy level are not filled.

15. Electron Configurations for Representative Elements
Lithium
1s2 2s1
Sodium
1s2 2s2 2p6 3s1
Potassium
1s2 2s2 2p6 3s2 3p6 4s1

16. Transition Elements
Transition elements connect the two sets of representative elements.
There are two types of transition elements:
Transition metals
Inner transition metals
They are classified based on their electron configurations.

17. Transition Metals
In atoms of a transition metal, the highest occupied s sublevel and a nearby d sublevel contain electrons.
These elements are characterized by the presence of electrons in d orbitals.

18. Inner Transition Metals
The inner transition metals appear below the main body of the periodic table.

19. Inner Transition Metals
In atoms of an inner transition metal, the highest occupied s sublevel and a nearby f sublevel generally contain electrons.
The inner transition metals are characterized by f orbitals that contain electrons.