Among the following elements, $X$ exhibits maximum catenation and $Y$ is the least abundant on earth. $X$ and $Y$ elements are

Give uses of carbon dioxide.

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

Red lead is an example of a/an .... oxide.

The element $X$ on reaction with conc. $HNO_3$ forms two acidic oxides $A$ and $B$ of different shapes. Element $Z$ on reaction with conc. $H_2SO_4$ forms two acidic oxides $A$ and $D$ of different shapes. What are $X$ and $Z$?

Holme signal can be given by using which of the following mixtures?