how many valence electrons are in a chlorine atom?
This means, that the number of electrons present in an chlorine atom is 17. The energy shells of an atom are in the order K, L, M â¦ So the electronic configuration of chlorine atom is: K, L, M = 2, 8, 7. Valence electrons are the number of electrons present in the outermost shell of an atom. The last shell of a chlorine atom has 7 electrons in it. Therefore, there are 7 valence electrons in an chlorine atom. Here is a video which gives a quick discussion of how to determine how many valence electrons atoms of different elements have.