Jawabanmu

2014-08-21T22:51:17+07:00
A.17 Cl- = 18 Cl -> 1s2 ,2s2 ,2p6, 3s2, 3p6
b. 20Ca2+= 18 Ca -> 1s2. 2s2. 2p6 .3s2. 3p6