Nuclear Physics Basics

Cory Carnley
3 min readApr 12, 2023


Nuclear physics is the branch of physics that deals with the structure of nuclei — the basic building blocks of matter. It studies the formation, stability and decay of nuclei to understand the fundamental forces in nature, their symmetries, and how they interact with one another to form different forms of matter.

Atoms are the basic building blocks of all chemical elements. They are made up of protons and neutrons, except hydrogen, which only has one proton.

Nuclear physics is the branch of science that deals with the structure and behaviour of these particles. It seeks to understand the interactions that bind nucleons in nuclei and how these bind them to each other and the rest of the universe.

The first step toward understanding nuclear physics is to develop a good understanding of the fundamental properties of atoms. This requires a thorough knowledge of the physical constants that govern their behaviour, such as the electron mass, charge, and speed of light.

Another crucial step is to learn how the strong interaction binds these atoms together. This explains how the lightest elements, including hydrogen (Z=1) and helium (Z=2), came into existence and how heavy nuclei are created during stellar evolution or in supernovae.

The nucleus is the most stable part of an atom, consisting of protons and neutrons. It is also the essential organelle in a cell, storing genetic information in DNA (deoxyribonucleic acid) and regulating cell growth, replication, and metabolism.

As a consequence, nuclear physics is involved in many fundamental questions that are crucial to the understanding of the universe and human existence. These include how the strong force binds nucleons together to form light nuclei, how heavy nuclei are synthesized, and how nuclear processes occur during stellar evolution and in supernovae.

The nucleus is a complex system involving many degrees of freedom. This makes it a unique challenge to understand. Nuclear physicists use a wide range of methods and techniques to address this problem.

Isotopes of a given element have the same chemical properties but different nuclear properties due to a difference in atomic number (Z) and mass numbers. For example, all isotopes of oxygen have 8 protons, but an oxygen atom with a mass of 18 has two more neutrons than an oxygen atom with a mass of 16.

Isotopic ratios of elements in water and solutes can indicate their sources or processes. Isotope fractionation occurs due to many physical, chemical, and biological processes and reactions.

Consequently, it is essential to understand how these fractionations affect the strength of chemical bonds involved in an element’s isotope composition. Isotope effects on the strength of bonds can be measured as changes in a molecule’s zero-point energy.

Stable isotopes can be measured using standard methods and combined with environmental isotopes to help deduce geochemical processes. They can also be used to test models derived from other techniques.

Radioactive decay occurs when an unstable atom of an element attempts to become stable, changing into a different but still unbalanced element by emitting ionizing radiation. A combination of strong and weak nuclear forces causes this process.

The ionizing radiation released during radioactive decay includes alpha particles, beta particles and gamma rays. These particles can penetrate matter, in decreasing order of their ability to do so, and can cause damage if they enter tissue or other objects.

Alpha particles were initially thought to be helium nuclei. Still, experiments with a beam of alpha rays passing through a glass window and then being reflected showed them to be high-speed electrons, similar to the cathode rays produced by electricity. The alpha particles also emitted characteristic X-rays and Auger electrons but were not accompanied by the emission of a neutrino.

Although the energy emitted in radioactive decay is distributed among the decay particles, the system mass and the system invariant mass are conserved throughout the decay, as is the system’s total energy.



Cory Carnley

Cory Carnley is a Gainesville resident and a native of Florida with a diverse set of skills and experience.