The most stable atoms are those of noble gases such as helium, neon, argon …..etc, Because their outermost energy level is filled with electrons, so, the atoms of these electrons do not undergo any...
The modern periodic table consists of 7 periods (horizontal rows), and 18 groups (vertical columns), The elements are arranged ascendingly according to their atomic numbers and the way to fill their atomic energy sublevels...
The mathematical solution of Schrodinger’s equation introduced four numbers that were called quantum numbers, to determine the energy of an electron in multi-electron atoms, we should know the four quantum numbers which describe it.
On heating atoms of pure elements – in a gaseous or vapor state – to a high temperature or exposing them to low pressure in an electrical discharge tube, they emit a radiation called...
