Effective Nuclear Charge :- 1. a. The stability of an electron in multi-electron atom is because total interactions (between electron and nucleus) are more than the repulsive interactions (between electrons). b. Attractive interactions of an electron increases with increase of positive charge (Ze) on the nucleus. c. Inner shell electrons partially shield the outermost electrons from the positive charge of the nucleus. The net positive charge experienced by the outermost electrons is known as Effective Nuclear charge . 2. Both the attractive and repulsive interactions depend upon the shell and shape of the orbital in which the electron is present . 3. For a given shell , Ze experienced by the electron decreases with increase of azimuthal quantum number .The energy of electrons in s-orbital will be lower (more negative) than that of p-orbital which have less energy than that of d-orbital a...