$$ \begin{aligned} \mathrm{XeF}_4+\mathrm{O}_2 \mathrm{~F}_2 & \longrightarrow X+\mathrm{O}_2 \\ X+\underset{(1 \text { mole })}{\mathrm{H}_2 \mathrm{O}} & \longrightarrow Y+2 \mathrm{HF} \end{aligned} $$

The shapes of molecules of $X$ and $Y$ respectively are

Identify the correct statements from the following.

A. In photosynthesis reaction, water is oxidised to oxygen.

B. An example for interstitial hydride is $\mathrm{MgH}_2$.

C. Sodium hexametaphosphate is used in the removal of permanent hardness of water.

Consider the following statements about group 13 elements.

A. $\mathrm{AlCl}_3$ gets stability by forming a dimer.

B. $\mathrm{BCl}_3$ is an electron deficient molecule.

C. $E_{M^{3+} / M}^{\circ}(\mathrm{V})$ is +1.26 for aluminium.

D. In +1 oxidation state thallium is unstable.

The incorrect statements are

What is the correct order of melting temperature of $\mathrm{C}, \mathrm{Si}, \mathrm{Ge}$ ?