Answer :
The answer is (3) neon. It depends on the electron number of these atoms. If they have 8 electrons at the outer layer, it is stable. (For He, it only has 2 electrons at the first layer is also stable.)
Answer;
- Neon
Explanation;
Neon is a noble gas (group 8 elements in the periodic table). Noble gases have an octet configuration or what we call stable configuration. All noble gases have outer energy shell with maximum number of valence electrons.
Neon therefore, has a stable electron configuration since it has an outer energy shell with maximum number of electrons.