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

When sodium is converted into sodium ion (Na⁺) then the effective nuclear charge of sodium (Na) is:

1. Increases 3 times approximately 

2. Increases 2 times approximately 

3. Decreases 2 times approximately 

4. Decreases 3 times approximately 

If Z_eff of element having atomic number 11 is 2.2, then Z_eff of elements having atomic number 12 and atomic number 20 are respectively :-

1. 2.85, 3.92

2. 3.92, 2.85

3. 2.2, 2.2

4. None of the above

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?

1. Na and Na⁺

2. Na and K

3. Cl and Cl^–

4. Mg and Mg⁺

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

Which is the correct order of ionization energies?