What type of gas is classified as a hydrocarbon gas?

Hydrocarbon gases are defined as gases that are primarily composed of hydrogen and carbon atoms. Natural gas fits this definition as it consists mainly of methane, which is a simple hydrocarbon (CH₄). In addition to methane, natural gas may also contain other hydrocarbons such as ethane, propane, and butane, but its primary component remains methane.

This classification is significant because hydrocarbon gases are primarily used as fuels and in various industrial applications, distinguishing them from the other options. Carbon dioxide, nitrogen, and oxygen do not fall into the category of hydrocarbon gases, as they either lack carbon (like nitrogen and oxygen) or do not meet the criteria of being a combination of hydrogen and carbon atoms (like carbon dioxide). Therefore, natural gas is correctly identified as a hydrocarbon gas.