What are hydrocarbons primarily composed of?

Hydrocarbons are organic compounds made up exclusively of carbon and hydrogen atoms. This unique composition allows for a wide variety of structures, such as chains and rings, which significantly influence their chemical properties and reactions. For instance, alkanes, alkenes, and alkynes are all types of hydrocarbons characterized by different arrangements and bonds between carbon and hydrogen.

Understanding the structure of hydrocarbons is foundational in organic chemistry, as they serve as the building blocks for more complex molecules. Many fuels, for example, are hydrocarbons, which release energy upon combustion. The other options include elements that are not part of hydrocarbons. For instance, options involving only oxygen or nitrogen would indicate compounds that are not purely hydrocarbons, which confirms that carbon and hydrogen are the only elements in their composition.