Group 1 (alkali metals)

All group 1 elements react with water to form alkaline solutions. 

They are very reactive because the have only one electron in their outer shell.

Reactivity increases down the group because the atoms get bigger.

Properties of group 1 metals :

• soft to cut
• shiny when cut but quickly tarnish in the air
• very low melting points compared to other metals
• very low densities compared to other metals (sodium, lithium and potassium float on water)
• react very easily with air, water and other elements such as chlorine. They are so reactive that they are stored in oil so they don't react with air
• their hydroxides and oxides dissolve in water to form alkaline solutions

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