# Nuclear Fission

# Nuclear Fission

**This lesson aligns with Next Generation Science Standards (NGSS) PS1.C**

**Introduction**

A nuclear reaction involves the change of identity or characteristics of an atomic nucleus produced by the bombardment of an energetic particle. The bombarding particle may either be any subatomic particle such as an alpha particle, a neutron, a proton, a gamma-ray photon, or a heavy ion. In any case, the subatomic particle must have enough energy to affect the atomic nucleus within the range of strong nuclear force. Nuclear fission is a common type of nuclear reaction that involves the splitting of a heavy nucleus into daughter nuclei with the help of low-energy neutrons. In this article, we will learn about nuclear fission, nuclear energy, and the role of nuclear fission in real life, etc.

**Nuclear Fission**

Nuclear fission refers to the subdivision of an atomic nucleus into two fragments of roughly equal mass. The process of nuclear fission may take place through natural spontaneous splitting by radioactive decay or can be induced by the excitation of an atomic nucleus with the bombardment of an energetic particle. The term fission was first discovered in the year 1938 by the German chemists Otto Hahn and Fritz Strassmann.

Nuclear fission reactions often release a tremendous amount of energy. The releasing energy can be accompanied by the emission of neutrons and gamma rays. In the fission process, the products that are formed always have a lower mass than the original. This missing mass is converted into nuclear energy.

**Examples of Nuclear Fission**

**1.**The most important example of nuclear fission is the splitting of Uranium-235. The diagram mentioned is a symbolic representation of a nuclear fission reaction. When the atomic nucleus of Uranium-235 is made excited with the bombardment of a neutron, it is converted to Uranium-236. It further splits into two lighter nuclei, Barium and Krypton.

The complete equation of this reaction is shown below:

[math]92235U + 01n rarr 56144Ba + 3689Kr + 301n+Q[/math]

Where Q is the energy released in this fission reaction, typically, the amount of energy released in the case of Uranium-235 is around 200Mev.

[math]92235U + 01n rarr 56144Ba + 3689Kr + 301n+200Mev[/math]

**2.**The splitting of Plutonium-239 is another example of nuclear fission. When a neutron strikes Pu-239 it is converted into lighter nuclei such as Xenon-137 and Zirconium-40. The complete equation is given below.

[math]94239Pu + 01n rarr 54137Xe + 10340Zr + 301n[/math]

**Nuclear Energy**

In the nuclear fission process, a tremendous amount of energy is released, radioactive products are formed, and neutrons are emitted. These neutrons can stimulate the fission reaction in the nearby nucleus of the fissionable element and start the chain reaction. Consequently, more neutrons are emitted, and more energy is released. That energy is known as nuclear energy. It is very beneficial for society as it has the potential to produce a significant amount of power without any emissions of pollutants. The nuclear energy released in this process can be determined by the famous Einstein’s energy-mass equation, which is [math]E = mc^2[/math].

E is the energy, m is the mass, and c is for speed of light.

**Application of Fission in Nuclear Power Plants**

One of the major real-world applications of a fission reaction is the production of electricity through nuclear power plants. Uranium and plutonium are often used for fission reactions in nuclear power reactors. Both are easy to initiate and control.

When a fission reaction takes place in Uranium or any heavy atom, the fission fragments release energy in the form of kinetic energy. Due to collision, that kinetic energy is converted into heat energy. The heat energy is used to produce steam, which is used to spin the turbine. As a result, the turbine rotates the generator, which produces carbon-free electricity.

**Summary**

- A nuclear reaction is a process in which one or more nuclides are produced from the collision of two nuclei, an atomic nucleus and a subatomic particle.
- Nuclear fission is a type of nuclear reaction that involves the splitting of a heavy nucleus into fragments of lighter nuclei.
- Nuclear fission can take place naturally by radioactive decay or artificially induced by the bombardment of a neutron.
- A tremendous amount of energy is released in such type of reaction.
- The production of electricity in the nuclear power plant is a worldwide application of nuclear fission.

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