Alkaline Earth Metals
The group 2 elements — beryllium through radium — which have two valence s electrons.
Formula / equation
ns²
Unit
Dimensionless
In depth
They form M²⁺ ions and are harder, denser and higher melting than group 1 because two electrons per atom strengthen metallic bonding. Their higher charge density gives less soluble hydroxides, carbonates and sulfates, and beryllium is anomalously covalent because of its very small size.
Examples in the real world
Magnesium burning with an intense white light; calcium carbonate as limestone, chalk and marble.