$a){}_{19}K:1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^1$    

$b){}_{34}Se:1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^4$

$c){}_{25}Mn:1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^5$

$d){}_{7}N:1s^{2}2s^{2}2p^3$