Which fossil fuel is primarily composed of methane? A) natural gas B) coal C) tar sand D) crude oil

What the question is really asking

You need to match the fossil fuel to the main chemical it contains. Methane is the simplest hydrocarbon, with the formula $CH_4$.

Identifying the fossil fuel that is mostly methane

• Natural gas is made mostly of methane ($CH_4$), often 70% to 90% or higher depending on the source.

Why the other options are not correct

• Coal is mostly solid carbon-rich material, not methane.
• Tar sands contain bitumen, which is a thick mixture of heavier hydrocarbons.
• Crude oil is a liquid mixture of many hydrocarbons, mostly larger than methane.

Quick check

If you see methane ($CH_4$), think “gas fuel used for heating and cooking,” which points to natural gas.