What is coal?

Give the percentage of carbon content in each of the following varieties of coal.

$\mathrm{a}.$ Peat     $\mathrm{b}.$Anthracite    $\mathrm{c}.$Lignite     $\text{d.}$ Bituminous coal

Name the following:

A thick black liquid with an unpleasant smell.

Name the following:

The variety of coal that burns with very little smoke and upto a very long time.

Name the following:

A tough, porous, and black substance that is used to manufacture steel.

Name the following:

A variety of coal which when burnt produces ash and sulphur compounds.