What is Nuclear energy?(explain about 100 words)10point

Nuclear energy means the energy generated from the activity of the nucleus. In general, two nuclear activities are found in the world. They are nuclear fission and nuclear fusion. Currently, all the nuclear energy we use in daily life are from nuclear fission. In the nature, there are some elements with high atomic weight such as Uranium (U). The nucleus is therefore not stable and they can break down into smaller nuclei and neutron to stablize itself. During the fission process, some mass is missing. According to the relativity, E=MC2. the missing mass has been converted to energy. We can utilize this energy for pushing the dynamo and produce electricity.

Nuclear fusion is a cleaner process in which the hydrogen is fused together to generate the helium. In the process, some mass is also missing and converted to energy. This nuclear fusion is in fact happening every in the Sun in which the heat and light is generated by nuclear fusion. This process is much cleaner. However, this process need a very high temperature to start. Practically, we cannot control such high temperature to start the fusion. In 60's, the hydrogen bomb is using this principle. It starts the atomic bomb to creat the high temperature and it can then initiate the fusion process of the hydrogen in the bomb.

About 27% of electricity used in Hong Kong comes from the Days Bay Nuclear Power Station in Shenzhen.In a nuclear power station,nuclear fuels break down in a controlled way to generate heat energy.The heat energy is used to boil water to steam.The steam drives a turbine,which in turn drives a generator to produce electricity.