Here's why:
* Coal is formed from ancient plant matter that has undergone intense heat and pressure over millions of years. This process breaks down the plant's complex molecules, including cellulose, into a mixture of hydrocarbons. Some of these hydrocarbons form ring-like structures, known as cyclic hydrocarbons.
* Petroleum and natural gas are primarily composed of straight-chain and branched-chain hydrocarbons, although they may contain small amounts of cyclic hydrocarbons.
Key takeaway: While all fossil fuels are primarily composed of hydrocarbons, coal is distinguished by the presence of significant amounts of cyclic hydrocarbons in its molecular structure.
