Explain the deviation in ionisation enthalpy of some elements from the general trend by using Fig. 3.2.

Question

Philoid · Accepted Answer

The ionisation enthalpy of elements varies across period and group. The ionisation enthalpy decreases down a group and increases as we move from left to right in a period. It is affected by the following parameters.

• Effective nuclear charge on the outermost electrons.

• Electron- electron repulsion force.

• Stability of the element due to half-filled and fully filled orbitals.