The incorrect match among the following options is : 

1.$$ $\left[\mathrm{Ar}\right]3{\mathrm{d}}^{5}4{\mathrm{s}}^1\to$ $4^{\mathrm{th}}$ $\mathrm{period},$ $6^{\mathrm{th}}$ $\mathrm{group}$

2. $$ $\left[\mathrm{Kr}\right]4{\mathrm{d}}^{10}\to$ $5^{\mathrm{th}}$ $\mathrm{period},$ ${12}^{\mathrm{th}}$ $\mathrm{group}$

3. $$ $\left[\mathrm{Rn}\right]6{\mathrm{d}}^{2}7{\mathrm{s}}^2\to$ $7^{\mathrm{th}}$ $\mathrm{period},$ $3^{\mathrm{th}}$ $\mathrm{group}$

4. $$ $\left[\mathrm{Xe}\right]4{\mathrm{f}}^{14}5{\mathrm{d}}^{2}6{\mathrm{s}}^2\to$ $6^{\mathrm{th}}$ $\mathrm{period},$ $4^{\mathrm{th}}$ $\mathrm{group}$

The element having electronic configuration [Kr]4d¹⁰4f¹⁴, 5s²5p⁶, 6s² belongs to:

1. s-block

2. p-block

3. d-block

4. f-block

Which of the following options shows an incorrect order of ionic radii?

1. Sr²⁺<Rb⁺<Br^-<Se^2-

2. Nb⁵⁺<Zr⁴⁺<Y³⁺

3. Co>Co²⁺>Co³⁺>Co⁴⁺

4. Ba²⁺>Cs⁺<Se^2-<As^3-

Which of the following pairs has the most significant size variation?

Given below are pair of species. Which pair has the largest difference in sizes? 

Which is the correct order of ionization energies?