Answer
a) 1s$^{2}$2s$^{2}$2p$^{2}$
b) 1s$^{2}$2s$^{2}$2p$^{6}$3s$^{2}$3p$^{6}$
c) 1s$^{2}$2s$^{2}$2p$^{6}$3s$^{2}$3p$^{6}$3d$^{8}$4s$^{2}$
Work Step by Step
a) 1s$^{2}$2s$^{2}$2p$^{2}$
b) 1s$^{2}$2s$^{2}$2p$^{6}$3s$^{2}$3p$^{6}$
c) 1s$^{2}$2s$^{2}$2p$^{6}$3s$^{2}$3p$^{6}$3d$^{8}$4s$^{2}$