Chemistry of Group 1 Elements. (The Alkali Metals)

For grades 9-12

State Standard 2.0

Interactions of Matter.

Gary Lennon

Group 1 Elements.

• Li Lithium• Na Sodium• K Potassium• Rb Rubidium• Cs Cesium• Fr Francium

• The Most reactive family of metals.• Reactivity increases DOWN the group.• Why?

Group 1 Elements.

• All Group 1 elements share the same electron configuration in their outer energy level.

• All are ns1, where n = energy level currently filling.

• All have a great desire to lose this one electron and thereby attain a stable full outer energy level.

• Reactivity increases down the group because of reduced nuclear shielding.

• The more energy levels there are between the single valence electron and the nucleus, the more that valence electron is shielded from the forces holding the atom together.

• This means it will lose that electron more readily.

• If we look back at the videos, we can now hazard a good guess at which of those elements is lowest in the group.

• All Group 1 metals are too reactive to exist in nature as the isolated element.

• Most sodium is found as sodium chloride (salt).

• Analogous to the reactivity of sodium, so chlorine (Group 17, Halogens) is exceptionally reactive but for a different reason.

• In this case, chlorine has an ns7 configuration, it needs 1 more electron to be stable.