Question

explain the reason for the variation of the first ionization energies of the third period element.

Answer 1

First ionisation energy generally increases going across Period 3. However, it needs more detailed consideration than the trend in Group 2 because:

The first ionisation energy drops between magnesium and aluminium before increasing again.The first ionisation energy drops between phosphorus and sulphur before increasing again.

To explain these dips, you need to think about the electronic configurations of these elements.

You can:

view a table of first ionisation energiesview a graph of first ionisation energieslearn about why the first ionisation energy increases going across Period 3
hope u are satisfied..!