How will you find the valency of chlorine, Sulphur and magnesium?
The valency of electrons is determined by electrons present in the outermost shell of an atom. Electrons present in the outermost shell of an atom are known as the valence elctrons. Those electrons determine the valency of that atom. The atomic number of chlorine is 17 and the electronic configuration is 2,8,7. Thus chlorine has 7 electrons in outermost shell and to complete its octet it needs 1 more electron. So the valency of chlorine is one. The atomic number of Sulphur is 16 and the electronic configuration is 2,8,6. Thus Sulphur has 6 electrons in outermost shell and to complete its octet it needs 2 more electron. So the valency of Sulphur is two. The atomic number of Magnesium is 12 and the electronic configuration is 2,8,2. Thus Magnesium has 2 electrons in outermost shell. It is easy to give away two valence electrons. So the valency of Magnesium is two.