Correct order of ionic radii:
\(O^{–2} > Mg^{+2}\)
This is because among isoelectronic species, the size of anions are greater than the size of cations.
Statement (II) is correct as both \(O^{–2}\) and \(Mg^{+2}\) are isoelectronic.
Hence, the correct option is (D): (A) is false but (R) is true.
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)

Cobalt chloride when dissolved in water forms pink colored complex $X$ which has octahedral geometry. This solution on treating with cone $HCl$ forms deep blue complex, $\underline{Y}$ which has a $\underline{Z}$ geometry $X, Y$ and $Z$, respectively, are
Identify the correct statements about alkali metals
A. The order of standard reduction potential \(\left( M ^{+} \mid M \right)\)for alkali metal ions is \(Na > Rb > Li\)
B. \(CsI\)is highly soluble in water.
C. Lithium carbonate is highly stable to heat.
D. Potassium dissolved in concentrated liquid ammonia is blue in colour and paramagnetic.
E. All the alkali metal hydrides are ionic solids.
Choose the correct answer from the options given below:
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)