In the year 1906, scientist Albert Einstein suggested that a mass can be changed into energy. In the times that followed some scientist realized that a tremendous amount of energy can be produced by splitting nucleus of an atom into parts. This is called nuclear fission. In this process a small difference in mass could be changed into energy.
mage via Wikipedia
An example is a uranium atom in nuclear fission. Some uranium nuclei and the nuclei of few elements split easily. The nucleus that splits gives off other elements,an energy, and about two neutrons. Once fission starts the splitting process will continue. The event will establish a chain reaction since the neurons that was produce split other uranium atom. An example of an uncontrolled chain reaction is the explosion of an atomic bomb. (sheet labels coupon)
To control the chain reaction the engineers have designed nuclear reactors. The nuclear reactors could produce energy from the chain reaction that will be used in homes and industry. Because the fuels in nuclear reactors are not pack closely,some scientist say they will not explode. Nuclear reactors comes in many safety systems because a nuclear explosion could be dangerous.
These reactors can make electricity. The energy from the reactors boils water and create a steam. The steam will make the blades of a machine (called turbine) to turn which operates a generator.
A fusion could also change a little mass into a lot of energy. This time by putting light nuclei together to make heavier ones. This is what the sun and other stars make to produce energy. They say that supply for fusion could be almost unlimited since a suitable fuel for a fusion reaction is a form of hydrogen found in the vast ocean water.
Scientist said that fusion reaction might be free from some of the problems faced by the fusion reaction. They say that there will be few radioactive materials that would be used or created in fusion activity.
The fusion reaction will work only when temperature are raised to and kept in a million degree Celsius. A temperature that is very difficult to manage in Earth laboratories.