The Periodic Table Finished, C3

Alkali Metals

• they are in group 1
• really reactive
• soft solids at room temperature
• low melting and boiling points (this decreases as it goes down the group)
• low densities - so lithium, sodium and potassium float on water
• they all react with air and water (reaction with water produces hydrogen gas and a metal hydroxide that is a strong alkali)
• they all have one electron in their outer shell, and lose this electron in reactions toform ionic compounds in which their ions have a single positive charge, e.g. Na+
• the group 1 elements get more reactive going down the group.

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