$A$ certain element forms a solid oxide which when dissolved in water forms an acidic solution. The element is:

Select the correct order of melting point:

Assertion : Stannous chloride gives grey precipitate with mercuric chloride,but stannic chloride does not do so.
Reason : Stannous chloride is a powerful oxidising agent which oxidises mercuric chloride to metallic mercury.

The silicate having one monovalent corner oxygen atom in each $SiO_4$ tetrahedron unit is:

The catenation tendency of $C$,$Si$ and $Ge$ is in the order $Ge < Si < C$. The bond energies (in $kJ \ mol^{-1}$) of $C-C$,$Si-Si$ and $Ge-Ge$ bonds,respectively,are:

Bleaching powder is obtained by the action of chlorine on which of the following?