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:

Which of the following statements are true and false?

${\mathrm{S}}_1: {\mathrm{IE}}_1$ of $\mathrm{Sr}>\mathrm{Rb}$ but ${\mathrm{IE}}_2$ for $\mathrm{Rb}>\mathrm{Sr}$.

${\mathrm{S}}_2:$ The ionic radii of ${\mathrm{Li}}^{+}, {\mathrm{K}}^{+}, {\mathrm{Mg}}^{2+}$and ${\mathrm{Al}}^{3+}$ in $\mathrm{Å}$ are $0.76, 1.38, 0.720$ and $0.535,$ respectively.

${\mathrm{S}}_3:$ The negative value of electron gain enthalpy of $\mathrm{Cl}>\mathrm{F}$ because there is weak electron-electron repulsion in a bigger $3\mathrm{p}$ subshell of $\mathrm{Cl}$  as compared to compact $2\mathrm{p}$ subshell of $\mathrm{F}$.

${\mathrm{S}}_4:$ The second ionization energy of copper is less than potassium.