Deutsch: Kohlenwasserstoff / Español: Hidrocarburo / Português: Hidrocarboneto / Français: Hydrocarbure / Italiano: Idrocarburi
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon.[1] Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls.[2] Aromatic hydrocarbons (arenes), alkanes, alkenes, cycloalkanes and alkyne-based compounds are different types of hydrocarbons.
The majority of hydrocarbons found on Earth naturally occur in crude oil, where decomposed organic matter provides an abundance of carbon and hydrogen which, when bonded, can catenate to form seemingly limitless chains.

In the environmental context, "hydrocarbon" refers to a compound that is made up of hydrogen and carbon atoms. Hydrocarbons can be naturally occurring or human-made, and can have both positive and negative effects on the environment. Here are some examples:

1. Methane: This is a simple hydrocarbon that is the primary component of natural gas. Methane is also produced by some microorganisms and is a potent greenhouse gas that contributes to climate change.

2. Oil: This is a complex mixture of hydrocarbons that is found underground and is used as a fuel for transportation and other purposes. Oil spills can have devastating impacts on the environment, including damage to wildlife and habitats.

3. Coal: This is a fossil fuel that is formed from the remains of ancient plants. It is a complex mixture of hydrocarbons and other compounds, and is a major source of greenhouse gas emissions when burned for energy.

4. Propane: This is a simple hydrocarbon that is used as a fuel for heating and cooking. Propane is produced from natural gas and is also a greenhouse gas.

Other terms that are similar to "hydrocarbon" in the environmental context include:

1. Organic compound: This refers to any compound that contains carbon atoms. Organic compounds can be natural or human-made, and include a wide range of chemicals such as pesticides, plastics, and pharmaceuticals.

2. Greenhouse gas: This refers to any gas that traps heat in the Earth's atmosphere and contributes to climate change. In addition to methane and propane, other greenhouse gases include carbon dioxide, nitrous oxide, and fluorinated gases.

3. Fossil fuel: This refers to any fuel that is derived from the remains of ancient plants and animals, such as coal, oil, and natural gas.

4. Petroleum: This is a more specific term for crude oil, which is a complex mixture of hydrocarbons that is refined into various fuels and other products.