which one of the following electronic configuration represents the element that forms simple ion with a charge of-3? (a)1s^2,2s^2,2p^6,3s^2,3p^1 (b)1s^2,2s^2,2p^6,3s^2,3p^3 (c)1s^2,2s^2,2p^6,3s^2,3p^6,3d^1,4s ^2 (d)1s^2,2s^2,2p^6,3s^2,3p^6