Oil is a liquid a little bit like syrup. It doesn't mix with water. It can be black or brown, depending on the type. It is used as a fuel. When it burns it makes heat. Heat is energy.
We use a lot of oil. We use it in our cars. We use it for heating. The world uses around 84 million barrels of oil every day.
Where it comes from
Oil actually comes from living things. Mostly it is plankton - tiny animals that float on the sea. These plankton lived millions of years ago. Now they are buried deep in the ground - usually 4-6km down. The weight of the 4-6km of ground has turned them into oil.
Deep in the ground
To get oil, you have to drill deep underground. The first people to drill for oil were the Chinese. They were drilling for oil using bamboo some 2,000 years ago. The Chinese word for 'oil' ( ) - literally 'rock oil' - was invented in 1088.
In 1859, the United States produced 2,000 barrels of oil. Ten years later, it was making more than 4 million barrels a year.
Oil is used to make petrol to power cars. It is used to make many other things too. It is used to make fuel for airplanes, and to make natural gas and diesel. Diesel is used in big lorries, or trucks.
Because we cannot make new oil, some people worry we will run out of it.
Most of the world's biggest oil reserves in the ground are more than half used up. Some people say this is a good thing. Oil makes a lot of the world's pollution. If we did not use so much oil, the air would be cleaner.
now do this
1 The world uses ... barrels of oil every day
a. 84 million
2 Oil comes from ...
c. tiny animals in the sea
3 Most oil is ... underground
1. a, 2. c, 3. b