Sketch and explain the shape of the graph obtained for the successive ionization energies of potassium using a logarithmic scale for ionization energy on the y-axis against number of electrons removed on the x-axis.

See the graph below.

Explanation:

I looked up the ionization energies of potassium and plotted them against the number of electrons removed.

The ionization energies increase smoothly except for big jumps from 1 ⟶ 2, 9 ⟶10, and 17 ⟶ 18.

The shell notation for potassium is 2, 8, 8, 1.

We can easily remove the first electron from potassium.

To remove the second electron, we must break into the stable, filled n = 3 level, so there is a large jump in energy.

Similarly, to remove the 10th electron, we must break into the stable, filled

n = 2 level.

To remove the 18th electron, we must break into the stable, filled n = 1 level.