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?

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

An LPG (Liquified Petroleum Gas) cylinder weighs 15.0 kg when empty. When full, it weighs 30.0 kg and shows a pressure of 3.0 atm . In the course of usage at $27^{\circ} \mathrm{C}$, the mass of the full cylinder is reduced to $24 \cdot 2 \mathrm{~kg}$. The volume of the used gas in cubic metre at the normal usage condition ( atm and $27^{\circ} \mathrm{C}$ ) is (assume LPG to be normal butane and it behaves ideally)