Non-metals generally contain ______ electrons in their outermost shell.

5, 6, 7 or 8 is the correct answer, because non-metals generally have 5-8 electrons in their outermost (valence) shell. Since their valence shell is nearly filled, non-metals usually gain or share electrons to achieve a stable octet configuration. Electronic configurations of some non-metals are: Oxygen 2,6; Fluorine 2,7; Sulphur 2,8,6; Chlorine 2,8,7.