Which one of the following is used to convert sunlight into electricity in photovoltaic material?

$Si$ reacts with $CH_3Cl$ at $573 \ K$ in the presence of $Cu$ powder to form methyl substituted chlorosilanes. Among the given methyl substituted chlorosilanes, whose yield is minimum?

For bleaching powder,which of the following statements is incorrect?

What is the value of $\angle S-S-S$ in the puckered $S_8$ ring of rhombic sulfur (in $^{\circ}$)?

An allotrope of carbon which exhibits only two types of $C-C$ bond distances of $143.5 \text{ pm}$ and $138.3 \text{ pm}$, is $....$

Give uses of Carbon and its compounds.