Hot concentrated sulphuric acid on reaction with which one of the following elements,produces two gaseous products?

Carbon monoxide gas is more dangerous than carbon dioxide gas. Why?

Identify the correct statement$(s)$ from the following: $I$. The catenation property of group $14$ elements decreases from carbon to tin. $II$. Fullerene $(C_{60})$ has $20$ five-membered carbon rings and $12$ six-membered carbon rings. $III$. $SiO_2$ is soluble in conc. $NaOH$.

In the following reaction,assign the nature of the product formed by the complete hydrolysis of the underlined atom at $R.T.$: $\underline{C}O + H_2O \longrightarrow \text{No reaction}$

Which of the following compounds is the most volatile among $CH_4, SiH_4, GeH_4, SnH_4$?

The element that does $NOT$ show catenation is