The element having the highest first ionization enthalpy is

Which of the following statements are correct about $$\mathrm{Zn}, \mathrm{Cd}$$ and $$\mathrm{Hg}$$ ?

A. They exhibit high enthalpy of atomization as the d-subshell is full.

B. $$\mathrm{Zn}$$ and $$\mathrm{Cd}$$ do not show variable oxidation state while $$\mathrm{Hg}$$ shows $$+\mathrm{I}$$ and $$+\mathrm{II}$$.

C. Compounds of $$\mathrm{Zn}, \mathrm{Cd}$$ and $$\mathrm{Hg}$$ are paramagnetic in nature.

D. $$\mathrm{Zn}, \mathrm{Cd}$$ and $$\mathrm{Hg}$$ are called soft metals.

Choose the most appropriate from the options given below:

The ascending acidity order of the following H atoms is

The correct IUPAC name of $$\mathrm{K}_2 \mathrm{MnO}_4$$ is