The species Ar, K⁺ and Ca²⁺ contain the same number of electrons. In which order do their radii increase?

$1. \mathrm{Ar} < {\mathrm{K}}^{+} < {\mathrm{Ca}}^{2+}$
$2. {\mathrm{Ca}}^{2+} < \mathrm{Ar} < {\mathrm{K}}^{+}$
$3. {\mathrm{Ca}}^{2+} < {\mathrm{K}}^{+} < \mathrm{Ar}$
$4. {\mathrm{K}}^{+} <\hspace{0.17em}\mathrm{Ar} < {\mathrm{Ca}}^{2+}$

Which of the following orders of ionic radii is correctly represented?

1. $H^{-}>H^{+}>H$

2. $N{a}^{+}>F^{-}>O^{2-}$

3. $F^{-}>O^{2-}>N{a}^{+}$

4. $N^{3-}>M{g}^{2+}>A{l}^{3+}$

Identify the wrong statement among the following: 

1. Amongst isoelectronic species, the smaller the positive charge on the cation, the smaller the ionic radius.
2. Amongst isoelectronic species, the greater the negative charge on the anion, the larger is the ionic radius.
3. The atomic radius of the elements increases as one moves down the first group of the Periodic Table.
4. The atomic radius of the elements decreases as one moves across from left to right in the 2nd period of the Periodic Table.

Which of the following represents the correct order of increasing electron gain enthalpy with negative sign for the elements O, S, F and Cl ?

1. Cl<F<O<S

2. O<S<F<Cl

3. F<S<O<Cl

4. S<O<Cl<F

 An amphoteric hydroxide among the following is : 

1.  $\mathrm{Be}{\left(\mathrm{OH}\right)}_2$

2.  $\mathrm{Sr}{\left(\mathrm{OH}\right)}_2$

3.  $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$

4.  $\mathrm{Mg}{\left(\mathrm{OH}\right)}_2$

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

1. s-block

2. p-block

3. d-block

4. f-block

An element whose IUPAC name is ununtrium (Uut) belongs to:

1. s-block element

2. p-block element

3. d-block element

4. Transition element

Consider the following electronic configuration of an element (P) :

                 [Xe]4f¹⁴5d¹6s² 

Then correct statement about element 'P' is :

1. It belongs to 6th period and 1st group

2. It belongs to 6th period and 2nd group

3. It belongs to 6th period and 3rd group

4. None of the above

If IUPAC name of an element is "unununium" then correct statement regarding element is: