[" Which one of the following electronic configuration of an atomhas the lowest "],[" ionisation energy "],[[" (1) "1s^(2)2s^(2)2p^(3)," (2) "1s^(2)2s^(2)2p^(6)3s^(1)],[" (3) "1s^(2)25^((2)/(2))2p^(5)," (4) "1s^(2)2s^(2)2p^(5)]]