Which of the following valence electrons experiences a maximum effective nuclear charge?

The screening effect of inner electrons will lead to 

a. Decrease in the ionization potential.

b. Increase in the ionization potential.

c. Decrease in electron affinity.

d. Increase in electron affinity.

The general electronic configuration of the outermost and penultimate shell of an element is $(\mathrm{n}-1){\mathrm{s}}^2(\mathrm{n}-1){\mathrm{p}}^6(\mathrm{n}-1){\mathrm{d}}^{\mathrm{x}}{\mathrm{ns}}^1.$

If $\mathrm{n}=5$ and $\mathrm{x}=5,$ then the number of protons in the nucleus of the element will be: