Among $$\mathrm{VO}_2^{+}, \mathrm{MnO}_4^{-}$$ and $$\mathrm{Cr}_2 \mathrm{O}_7^{2-}$$, the spin-only magnetic moment value of the species with least oxidising ability is __________ BM (Nearest integer).

(Given atomic member $$\mathrm{V}=23, \mathrm{Mn}=25, \mathrm{Cr}=24$$)

The ratio of number of oxygen atoms to bromine atoms in the product Q is _________ $$\times 10^{-1}$$.

Total number of species from the following with central atom utilising $$\mathrm{sp}^2$$ hybrid orbitals for bonding is ________.

$$\mathrm{NH}_3, \mathrm{SO}_2, \mathrm{SiO}_2, \mathrm{BeCl}_2, \mathrm{C}_2 \mathrm{H}_2, \mathrm{C}_2 \mathrm{H}_4, \mathrm{BCl}_3, \mathrm{HCHO}, \mathrm{C}_6 \mathrm{H}_6, \mathrm{BF}_3, \mathrm{C}_2 \mathrm{H}_4 \mathrm{Cl}_2$$

If the function $$f(x)=\left(\frac{1}{x}\right)^{2 x} ; x>0$$ attains the maximum value at $$x=\frac{1}{\mathrm{e}}$$ then :