Among the given group $14$ elements,the one with highest density is

The $(Si_2O_5)_n^{2n-}$ anion is obtained when:

The silicate anion in the mineral kinoite is a chain of three $SiO_4$ tetrahedra,that share corners with adjacent tetrahedra. The charge of the silicate anion is

Gas $A$ is bubbled through slaked lime when a white precipitate is formed. On prolonged bubbling,the precipitate is dissolved. On heating the resultant solution,the white precipitate reappears with the evolution of gas $B$. The gases $A$ and $B$ respectively are

When graphite is heated at $300^{\circ} C$ with potassium vapour, it forms $C_8K$ compound that shows one of the following property.

The element $X$ which forms a stable product of the type $XCl_4$ is $....$