Identify the correct statements from the following.

(I) Au is soluble in aqua regia but not Pt .

(II) Among the oxoacids of chlorine highest oxidation state possible for chlorine is +7 .

(III) Among the hydrogen halides lowest boiling point is for HCl .

(IV) The order of stability of oxides of halogens is $\mathrm{Cl}>\mathrm{Br}>\mathrm{I}$.

Which of the following sequence is correct for decreasing order of ionic radius?

The successive ionisation energies (starting from the 1 st ) of an element are $801,2430,3660,25,000$ and $32,800 \mathrm{~kJ} \mathrm{~mol}^{-1}$, respectively. The element is

Assertion (A) The ionic radii of the alkaline earth metals are smaller than those of alkali metals in the same period.

Reason (R) Alkali metals have higher nuclear charge than that of the alkaline earth metals.

The correct option among the following is