Răspuns :

Li:1s2,2s1
K:1s2,2s2,2p6,3s2,3p6,4s1
Na:1s2,2s2,2p6,3s1
B:1s2,2s2,2p1
Al:1s2,2s2,2p6,3s2,3p1
N:1s2,2s2,2p3
P:1s2,2s2,2p6,3s2,3p3
F:1s2,2s2,2p5
Cl:1s2,2s2,2p6,3s2,3p5
Z-ul il iei din sist periodic: 3,19,11,5,13,7,15,9,17