Answer: 8 electrons
Explanation: Valence electrons are the electrons in the outermost shell of an atom and they are important in chemical reactions.
Atoms are happy when they follow the octet rule which states that 2 electrons can go in the first shell and 8 electrons can go in the other shells.
Electrons are happy when they have a full outer shell which usually needs to be 8 electrons. However, some of the smaller elements like helium are happy because they can hold a max of 2 electrons and helium has 2 electrons since it has 2 protons in its core as well as 2 electrons in its energy levels.