The molar conductances of $\mathrm{Ba}(\mathrm{OH})_2, \mathrm{BaCl}_2$ and $\mathrm{NH}_4 \mathrm{Cl}$ at infinite dilution are $523 \cdot 28,280 \cdot 0$ and $129.8 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$ respectively. The molar conductance of $\mathrm{NH}_4 \mathrm{OH}$ at infinite dilution will be

The common stable oxidation states of Eu and Gd are respectively

Which one among the following compounds will most readily be dehydrated under acidic condition?

$$\begin{aligned} &{ }_5 \mathrm{~B}^{10}+{ }_2 \mathrm{He}^4 \rightarrow \mathrm{X}+{ }_0 \mathrm{n}^1\\ &\text { In the above nuclear reaction ' } X \text { ' will be } \end{aligned}$$