Alkaline earth metals
The alkaline earth metals form group 2. Two ns² valence electrons, a stable +2 oxidation state. Less reactive than the alkalis but still very electropositive.
Beryllium, magnesium, calcium, strontium, barium and radium make up this family. Their chemistry is dominated by the +2 state; their oxides form strong bases (lye, lime water) when dissolved in water.
Calcium and magnesium are essential to biology (bones, chlorophyll) and very abundant in the Earth's crust. Barium and strontium have medical uses (digestive imaging, bone treatments); radium is radioactive and was used in the early days of radiotherapy.
In pure form, all of these metals burn in air with a very characteristic coloured flame, exploited in fireworks: red for Sr, green for Ba.