Methane and ethane are the two simplest hydrocarbons. Methane is one carbon atom connected to four hydrogen atoms. It is a flammable gas produced from the decay of natural material.
Propane is three carbon atoms in a chain surrounded by six hydrogen atoms. This is a flammable gas that is typically used in grills. Butane is four carbon atoms in a chain surrounded by eight hydrogen atoms. This is a liquid used in cigarette lighters.
Hydrocarbons are molecules composed only from hydrogen and carbon. Each carbon can have four connections or bonds to other atoms, and each hydrogen can have one. The chains can join ends to form a ring, and cyclohexane is a hexagon of six carbon atoms surrounded by twelve hydrogen atoms. This is commonly used as a solvent.