Nuclear Reaction

In nuclear chemistry and physics, a nuclear reaction is where two nuclei or nuclear particles collide to produce different products than the original particles. Also note that the reaction can have more than two colliding particles, but such an event is rare. In case the particles collide with each other without undergoing any change, then the process becomes elastic collision and not a reaction. You can represent the nuclear reaction in an equation similar to a chemical equation, balanced analogously. And nuclear decays too can get represented in the same manner. In this article, you can learn what is a nuclear reaction, types of nuclear reaction, and some insightful frequently asked questions.    

Nuclear Reaction Definition 

Nuclear reaction refers to a process where one or more nuclides get produced from the collision of atomic nuclei or one atomic nucleus and a subatomic particle. The nuclides obtained from nuclear reactions are not the same as reacting nuclei or parent nuclei. Popularly, there are two nuclear reactions named as nuclear fission and nuclear fusion reactions. 

In nuclear fission, a heavy nucleus tends to absorb neutrons or relatively lighter particles. And further, it splits into two or lighter nuclei. Whereas, nuclear fusion refers to a process where two light nuclei collide to form a single yet heavy nucleus. The term ‘nuclear reaction’ refers to external changes occurring on atomic nuclei. 

Below are specific processes that don’t qualify to be nuclear reactions. These processes appear similar to a nuclear reaction. But, these are spontaneous and not induced like a nuclear reaction.  

  • Nuclear Decay: It’s a process where an unstable nucleus tends to emit radiation. The sole purpose of doing so is losing energy. 

  • Spontaneous Fission Reactions: These are reactions taking place without neutrons and thus, don’t get induced. 

  • Nuclear Scattering Process: In this process, collision and separation of atomic nuclei take place without altering the nuclear composition. It’s a mere transfer of momentum and energy. 

Types of Nuclear Reactions 

Nuclear fission and nuclear fusion are the two most common types of reactions out there. You can learn about it in the following sections. 

Nuclear Fission

Nuclear fission reaction is nothing but the splitting of an atomic nucleus into two or lighter nuclei. Such reactions release a significant amount of energy, along with the emission of neutrons and gamma rays. In a fig. 1 below, you can see a representation of nuclear fission. 

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The nuclear fission was first discovered by German chemists Otto Hahn and Fritz Strassmann in 1938. The energy obtained from the reaction gets used further to produce electricity in nuclear power plants. It happens when the heat obtained from nuclear reactions turn the water into steam. And that steam rotates the turbines to give out electricity. 

Nuclear Fusion

In nuclear fusion reactions, two atomic nuclei come together and form into a single nucleus. Subatomic particles like protons or neutrons get obtained as products during nuclear fusions. Below is an illustration of the nuclear fusion reaction, as shown in fig. 2. 

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The above figure shows a fusion reaction between deuterium and tritium that gives out helium and a neutron too. Typically, these fusion reactions take place at the core of the sun and other stars. These reactions end up losing mass and giving out a tremendous amount of energy. 

FAQ (Frequently Asked Questions)

1. What is Nuclear Energy? 

In alpha and beta decay, energy gets released in the way of the kinetic energy of the daughter nuclide and radioactive emission. That is nothing but nuclear energy itself. Primarily, nuclear energy gets derived from the loss of mass during nuclear reactions. Two nuclear reactions give out an enormous quantity of energy. They are nuclear fission and nuclear fusion reactions. A nuclear reaction is a process where two nuclei or nucleus of an atom and a subatomic particle from outside the atom collide. Such reactions take place naturally as well as artificially to produce nuclear energy, in a controlled manner, on-demand.