The alkali metal group is the 1st column in the periodic table, which means alkali metals have a single electron on their valence shell they wish to lose. This means that all alkali metals are highly reactive, as can be seen in the explosive reaction of sodium with water Experiment: Sodium soup​. To prevent reactions with water vapour in the air, they must be stored submerged, like Li, lithium (litium)​ in paraffin oil.

• metals
  • except for the nonmetallic H, hydrogen (vety)​
• soft
• low in density
• highly reactive
  • form ions of charge 1+
• as compounds in nature

Under every-day conditions, H, hydrogen (vety)​ is a nonmetal, but under extreme conditions, it exhibits metallic behaviour.