What is the shape of monoclinic sulphur?

Which of the following methods is $NOT$ used for the concentration of an ore?

$A$ non-metal $X$ exists in two different forms $Y$ and $Z$. $Y$ is the hardest natural substance, whereas $Z$ is a good conductor of electricity. Identify $X$, $Y$ and $Z$.

An alkali metal $A$ gives a compound $B$ (molecular mass $= 40$) on reacting with water. The compound $B$ gives a soluble compound $C$ on treatment with aluminium oxide. Identify $A$,$B$ and $C$ and give the reaction involved.

Which of the following represents the correct order of reactivity of metals?

Which metal is stored in kerosene?