Question

which of the following represents a stable octet? A 1s2 2s2 2p6 3s2 3p6 4s2
B [He] 2s2 2p3
C 1s2 2s2 2p1
D [Ne] 3s2 3p6

Answer 1

[Ne]3s^23p^6  ( answer D)   represent a sample of an octet. Octet  is the tendency   of  an atom  to have  eight  electrons  in the valence  shell.  [Ne]3s^2 3p^6   is an  octet   since  its  valence  electron   that is3s^23p^6  has eight  electrons.