The minimum amount of energy required to remove the most loosely bound electron from an isolated atom in the gaseous state in known as ionisation energy or ionisation enthalpy (IE_1) of the element. The energy required to remove the second electron from the monovalent cation is called second ionisation enthalpy (IE_2). Similarly, we have third, fourth ..... inonisation enthalpies. The values of ionisation energy depends on a number of factors such as (i) size of the atom (ii) screening effect (iii) nuclear charge (iv) half filled and fully filled orbitals (v) shape of orbital. In a group, the ionisation energy decreases from top to bottom. In a period, the value of ionisation energy increases from left to right. The first ionisation energy of Mg, Al, P and S follows the order:

The minimum amount of energy required to remove the most loosely bound

1.	The minimum amount of energy required to remove the most loosely bound electron from an isolated atom in the gaseous state in known as ionisation energy or ionisation enthalpy (IE_1) of the element. The energy required to remove the second electron from the monovalent cation is called second ionisation enthalpy (IE_2). Similarly, we have third, fourth ..... inonisation enthalpies. The values of ionisation energy depends on a number of factors such as (i) size of the atom (ii) screening effect (iii) nuclear charge (iv) half filled and fully filled orbitals (v) shape of orbital. In a group, the ionisation energy decreases from top to bottom. In a period, the value of ionisation energy increases from left to right. The first ionisation energy of Mg, Al, P and S follows the order:
Answer» <P>`MG LT Al lt P lt S` `Al lt Mg lt P lt S` `Al lt Mg lt S lt P` `Mg lt Al lt S lt P` ANSWER :C