(a, b, c, d) The active nitrogen is more reactive than molecular nitrogen because it contain

atomic nitrogen. Active nitrogen when reacts with H 2 S blue solid is obtained because of the formation of sulphur nitride of m.f. (NS) x The nitrogen atoms have three unpaired electrons. When two such atoms combine, an excited nitrogen molecule molecule with four unpaired electrons, which then rearrange to give diamagnetic . In this combination process the energy liberated produces yellow afterglow.