Which gas is responsible for acid rain?

What is the chemical formula of alumina?

Of the three metals $X, Y$ and $Z$,$X$ reacts with cold water,$Y$ with hot water,and $Z$ with steam only. Identify $X, Y$ and $Z$ and also arrange them in the order of increasing reactivity.

$A$ non-metal $A$ is an important constituent of our food and forms two oxides $B$ and $C$. Oxide $B$ is toxic,whereas $C$ causes global warming.
$(a)$ Identify $A$,$B$,and $C$.
$(b)$ To which Group of the Periodic Table does $A$ belong?

$(i)$ Name a metal which does not stick to glass.
$(ii)$ Name the metal which is commonly used in thermite welding.
$(iii)$ What is the nature of zinc oxide?

What is the process of extracting a metal from its ore and obtaining it in a pure form called?