The 2p_x, 2p_y and 2p_z orbitals of atom have identical shapes but differ in their _____.

The light radiations with discrete quantities of energy are called ______.

The uncertainty principle and the concept of wave nature of matter were proposed by ______ and ______ respectively. (Heisenberg Schrodinger, Maxwell, de Broglie)

Elements of the same mass number but of different atomic numbers are known as ____.