The s-Block Elements

• Group 1 elements: lithium, sodium, potassium, rubidium, caesium, and francium

• Called alkali metals because their hydroxides are alkaline in nature

  Electronic Configuration

• General outer electronic configuration is ns¹.

  Physical Properties

• Silvery white, soft, and light metals

• Density increases down the group. (exception: Na is denser than K)

• Low melting and boiling points − Reason: weak metallic bond due to the presence of only one electron in the outermost shell

Alkali metals form oxides on combustion.

• The stability of peroxides or superoxides increases on moving down the group (i.e…