Question

An element has an atomic number 17. How many electrons are present in K , L and M shells of the atom?

Answer 1

This means, that the number of electrons present in an chlorine atom is 17. Where k, l, ,m are the shells/orbits/ energy levels of an chlorine atom. Valence electrons are the number of electrons present in the outermost shell of an atom. Now, the last shell of chlorine atom has 7 electrons in it.