Nuclear Reaction Explained in Chemistry

Nuclear Reaction is an essential concept in chemistry and physics because it explains how elements change their identity and release large amounts of energy. Understanding nuclear reactions helps students learn about stars, electricity production, and atomic changes, making this topic both practical and important for your chemistry syllabus.

What is Nuclear Reaction in Chemistry?

• A nuclear reaction is a process in which the nucleus of an atom changes, resulting in the transformation of one or more nuclides into new products. 
• Unlike chemical reactions—which involve only electrons—a nuclear reaction alters the number of protons and neutrons within the nucleus. 
• This topic is closely related to radioactive decay, nuclear fission, and nuclear fusion, making it a pillar of physical chemistry.

Types of Nuclear Reactions

Nuclear reactions come in various forms, but these are the four main types you should know:

• Nuclear Fission: A heavy nucleus splits into lighter nuclei, releasing energy. Example: Splitting of Uranium-235.
• Nuclear Fusion: Two light nuclei combine to form a heavier nucleus, as in the Sun's core. Example: Hydrogen fusion to form Helium.
• Radioactive Decay: Spontaneous breakdown of an unstable nucleus, emitting alpha, beta, or gamma rays.
• Artificial Transmutation: Changing one element into another using high-energy particles.

Molecular Formula and Composition

In a nuclear reaction, we represent the process using an equation: a + X → Y + b, where X is the target nucleus, a is a bombarding particle, Y is the product nucleus, and b is an emitted particle like a neutron, alpha, or beta.

Preparation and Synthesis Methods

Nuclear reactions are prepared in labs or nuclear reactors by bombarding nuclei with subatomic particles. For example, nuclear fission occurs when Uranium-235 absorbs a neutron and splits. Fusion typically requires very high temperatures, like those in stars or hydrogen bombs, to force nuclei together.

Physical Properties of Nuclear Reaction

Nuclear reactions are not defined by classic physical properties like color or state but by the changes they cause inside atoms. They release much more energy than ordinary chemical reactions, often as heat, light, or radiation, and are accompanied by a small but measurable loss of mass (the mass defect).

Chemical Properties and Reactions

Nuclear reactions involve breaking and forming nuclei, not molecules. They can convert one element into another, produce radiation, and are governed by laws of conservation—both mass number and atomic number are balanced in every nuclear equation.

Nuclear Reaction vs Chemical Reaction

Nuclear Reaction	Chemical Reaction
Occurs in the nucleus; changes protons/neutrons	Occurs with electrons; atoms keep their identity
Can change one element to another	Cannot change elements, only compounds formed
Releases huge energy (millions of times more)	Energy change is much smaller
Mass defect occurs due to E=mc²	No measurable mass change

Step-by-Step Reaction Example

1. Start with Uranium-235 as the target nucleus and a neutron as the bombarding particle.

2. Write the balanced nuclear equation:


3. Check that both the mass numbers (top) and atomic numbers (bottom) are equal on both sides.

4. Notice three new neutrons are released, which can trigger more fission reactions (chain reaction).

Frequent Related Errors

• Not balancing mass and atomic numbers in nuclear equations.
• Mixing up nuclear and chemical reaction processes.
• Ignoring that small mass loss equals large energy release (E=mc²).
• Assuming all radiation is a result of nuclear reactions (some can be non-nuclear).

Uses of Nuclear Reaction in Real Life

Nuclear reactions are used for generating electricity in nuclear power plants, running smoke detectors, treating cancer (radiation therapy), and dating archaeological finds (carbon dating). They also power the Sun and other stars through the fusion of hydrogen into helium.

Relation with Other Chemistry Concepts

Nuclear reactions link closely with atomic structure, isotopes, and the mass defect. These concepts help explain the origin of elements and the release of energy in nuclear processes.

Lab or Experimental Tips

Always remember: when writing nuclear equations, check the sum of all atomic and mass numbers on both sides. Vedantu educators suggest drawing the equation vertically and checking each value for balance to avoid common mistakes.

Try This Yourself

• Write a nuclear equation for the radioactive decay of Carbon-14.
• Find out whether a fission or fusion reaction occurs inside the Sun.
• List three devices that use nuclear reactions in everyday life.

Final Wrap-Up

We explored nuclear reaction—how it changes atomic nuclei, the difference between fission and fusion, and why so much energy is released. This topic connects atomic theory with real-world technology.