Petrol is actually fossil fuel consisting of complex mixture of hydrocarbons of different molecular weights and other organic compounds found under the earth’s surface. It takes more than thousand years for oil molecules to form from the remains of creatures, which existed millions of years ago, went through some chemical changes and got compre-ssed into sedimentary rock.
Later, such compressed rock becomes more compressed because of pressure caused from sea or ocean and by addition of sand and salt to it. Next to that, again chemical changes take place and that gets converted into the combination of hydrogen and carbon where heat and pressure plays a very important role. In this way, organic matter changes into firstly a waxy material called kerogen and then because of more heat and pressure get converted into liquid and gaseous hydrocarbons and from such hydrocarbons petroleum occurs which gives petrol, diesel, etc. after refining it.
