\(\text{M+ : 1s22s22p63s23p6(2/8/8)}\)
\(\rightarrow\)e =18
Ta có M -e =M+
\(\Leftrightarrow\)19e -e = 18e
\(\text{CHe: 1s22s22p63s23p64s1(2/8/8/1)}\)
\(\rightarrow\) M là Kali (K)
M+ có e= 18; p=19
\(\text{X2- : 1s22s22p63s23p6(2/8/8)}\)
\(\rightarrow\)e =18
Ta có : \(\text{X + 2e = X2-}\)
\(\Leftrightarrow\) 16e + 2e = 18e
\(\text{CHe : 1s22s22p63s23p4(2/8/6)}\)
\(\rightarrow\) X là O
X2- có e= 18; p=16