Identify each of the atom which has the following electron configuartions (a) 1s2-2s2-2p6-3s2-3p1 (b) 1s2-2s2-2p6-3s2-3p5 (c) 1s2-2s2-2p6-3s2-3p6-4s2 (d) which of the three has the largest ionization energy Ei1 (e) which of the three has the electron affinity Eea~0