Group 1 (Alkali Metals)

Alkali metals are found in Group 1 of the periodic table.
They include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr).
These metals are characterised by their soft, silvery appearance, and they are highly reactive.
Being in the same group, they share similar properties and similar reactivity patterns due to the structure of their outer electron shell.
Alkali metals are stored in oil, as they react violently with both water and oxygen from the air.

Alkali metals increase in reactivity down the group.
They have low melting and boiling points, which decrease down the group.
They are soft and can be easily cut with a knife.
Alkali metals are low density; lithium, sodium and potassium are less dense than water.

Alkali metals have one electron on their outer shell, which is why they are incredibly reactive.
They will willingly donate this outer electron in chemical reactions.
Alkali metals react violently with water, producing hydrogen gas and alkaline solutions.
When alkali metals react with oxygen, they form metal oxides. More reactive alkali metals can form peroxides or superoxides.
Alkali metals also react with chlorine, forming metal chlorides.

Reaction with Water: Alkali Metals + Water -> Alkali Metal Hydroxide + Hydrogen
Reaction with Oxygen: 4 Alkali Metals + O2 -> 2 Alkali Metal Oxides
Reaction with Chlorine: 2 Alkali Metals + Cl2 -> 2 Alkali Metal Chlorides

Due to their reactivity, alkali metals are typically handled with caution in the lab.
It’s necessary to avoid exposing alkali metals to air or moisture; they are stored in air-tight containers filled with inert oil.
When reacting alkali metals with water or halogens, ensure the setup is designed to contain any explosive reactions.