Question

Lithium Sodium and potassium were put in the same group on the basis of similar properties.

What is the similarity in their properties ?

Answer 1

The following are the similarities between Lithium, Sodium, and Potassium :

• The s-block elements having only one electron in their s-orbital are called group one or alkali metals.
• They all are placed in the first group.
• Since they have one electron in the outermost shell so they can easily lose the outermost electron and acquire inert gas configuration hence they all have a valency of +1.
• They all are highly reactive metals.
• They all liberate hydrogen gas on reaction in water, the reaction is as:$\mathrm{Na}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to \mathrm{NaOH}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)$.
• They all are good reducing agents.
• They are not found in nature as a free element, but generally as salts.
• They have a low density when compared to other metals.