<Dd> C H + 3n + 1 / 2 O → (n + 1) H O + n CO + energy . </Dd> <P> Burning of hydrocarbons is an example of an exothermic chemical reaction . </P> <P> Hydrocarbons can also be burned with elemental fluorine, resulting in carbon tetrafluoride and hydrogen fluoride products . </P> <P> Extracted hydrocarbons in a liquid form are referred to as petroleum (literally "rock oil") or mineral oil, whereas hydrocarbons in a gaseous form are referred to as natural gas . Petroleum and natural gas are found in the Earth's subsurface with the tools of petroleum geology and are a significant source of fuel and raw materials for the production of organic chemicals . </P>

How does the name hydrocarbon give clues about the composition of hydrocarbons