Oil, naphtha or ground oil, is a natural flammable mineral oil extracted from underground, consisting of hydrocarbons, with a consistency thicker than water, dark colored, unrefined, with a unique odor. It consists of the Latin words "petra" meaning stone and "oleum" meaning oil.
Gas is one of the 4 fundamental states of matter. In this state, the density of the matter is very low and its fluidity is extremely high. Gaseous substances do not have a definite shape or volume. When a solid substance is heated, it changes from solid to liquid and from liquid to gas. This situation is called phase change.