Consider the first order reaction $\mathrm{R} \rightarrow \mathrm{P}$.

The fraction of molecules decomposed in the given first order reaction can be expressed as

A monoatomic anion (A ) has 45 neutrons and 36 electrons. Atomic mass, group in the periodic table and physical state at room temperature of the element (A) respectively are

Given below are two statements :

Statement I : The covalency of oxygen is generally two but it can exceed upto four. The oxidation state of oxygen in $\mathrm{SO}_2$ is -2 and in $\mathrm{OF}_2$ it is +2 .

Statement II : The anomalous behaviour of oxygen when compared to the other elements of group 16 is due to its small size and high electronegativity.

In the light of the above statements, choose the correct answer from the options given below

The correct statements among the following are,

A. $\mathrm{Mo}(\mathrm{VI})$ and $\mathrm{W}(\mathrm{VI})$ are less stable than $\mathrm{Cr}(\mathrm{VI})$.

B. $\mathrm{Ce}^{4+}$ and $\mathrm{Tb}^{4+}$ are oxidant while $\mathrm{Eu}^{2+}$ and $\mathrm{Yb}^{2+}$ are reductant.

C. Cm and Am have seven unpaired electrons.

D. Actinoid contraction is greater from element to element than lanthanoid contraction.

Choose the correct answer from the options given below :