When sodium is dissolved in liquid ammonia is solution of deep blue colour is obtained. The colour of solution is due to

The blue colour of the solution is due to the ammoniated electron which absorbs energy in the visible region of light and thus impart blue colour to the solution. The solution are paramagnetic and on standing slowly liberate hydrogen resulting in the formation of amide. 3 2 2 1 2 am am M e NH l MNH H g → (Where ‘am’ denotes solution in ammonia) In concentrated solution, the blue colour changes to bronze colour and becomes diamagnetic.