3 Li 1s2,2s1
11 Na 1s2,2s2,2p6,3s1
19 K 1s2,2s2,2p6,3s2,3p6,4s1
5 B 1s2,2s2,2p1
13 Al 1s2,2s2,2p6,3s2,3p1
7 N 1s2,2s2,2p3
15 P 1s2,2s2,2p6,3s2,3p3
9 F 1s2,2s2,2p5
17 Cl 1s2,2s2,2p6,3s2,3p5
Acele numere din fata elementelor reprezinta Z,nr de electroni din invelis si nr de protoni din nucleu
