Neutrons 

At the heart of an atom – the nucleus – lies a fundamental particle known as a neutron, a neutral subatomic particle invisible to the naked eye, providing essential support and stability to the structure of an atom. These subatomic particles, alongside protons, determine the mass of an atom, which also influences the chemical and physical properties of an atom. Owing to the wide range of properties possessed by neutrons, understanding this vital part of an atom is important.

1.0Definition of Neutrons

Neutrons are subatomic particles in the centre or core of an atom and were discovered by British physicist James Chadwick in 1932. Neutrons are neutral particles, meaning they don’t possess any charge on themselves. It is one of the three core subatomic particles of an atom, which are protons, neutrons, and electrons. Neutrons play a crucial role in calculating the atomic number of an atom, as the sum of protons and neutrons equals the atomic mass. 

2.0Properties of Neutrons

1. Neutron Mass: Neutrons have a constant mass of approximately 1.675 × 10^-27 kg, which is almost equal to the mass of a proton. 
2. Neutron Charge: Neutrons don’t carry any charge on themselves, meaning these are electrically neutral. 
3. Location: Neutrons, alongside protons, are located in the dense central core or nucleus of an atom bound by strong nuclear forces.   
4. No effect of Electric field: The absence of charge on a neutron helps the neutrons to pass through matter without being deflected by its electric field.
5. Neutron Scattering: When Neutrons are scattered in a material, it is known as neutron scattering, which is used in material science and chemistry to study the internal structure of materials. 
6. Effect of Magnetic Field: Although unaffected by electric field, neutrons are greatly affected by magnetic field due to their magnetic moment arising from the spin of neutrons. 

3.0Neutron-Related Phenomena

Neutrons give rise to some of the most important natural phenomena, which include: 

• Isotopes: Isotopes are atoms of the same elements with the same number of protons but different neutrons. For example, Carbon -12 (6 protons and 6 neutrons) and Carbon – 14 (6 protons and 8 neutrons). 
• Neutron Decay: A free neutron (not bound within a nucleus) is unstable and, over time, continuously decays into proton, electron, and then antineutrino in the process called beta decay. Beta decay is a process with a half-life of approximately 10 minutes.
• Neutron Star: When a star goes under supernova, it may collapse into a neutron star, which is a dense and concentrated remnant of the star that is mostly made of neutrons. These stars are incredibly dense with extremely high and strong gravity. 

4.0Neutrons and Elements

The interactions of neutrons within atomic nuclei give rise to various isotopes and influence the stability and properties of elements. Some of these elements are: 

Potassium Neutrons

Potassium is an element with atomic number 19, and it has isotopes that include neutrons in their nuclei. For example, the isotope potassium-40 contains 21 neutrons in its nucleus and is radioactive. This isotope also goes under beta decay, which emits a beta particle and transforms the potassium atom into a different element. This process has revolutionised the way of dating objects and materials, geological samples and studying the Earth’s age.

Neutrons in Hydrogen

Hydrogen is the simplest & most abundant element in the universe, and it primarily exists as hydrogen-1 (protium), which has no neutrons in its nucleus. However, hydrogen also has isotopes deuterium (hydrogen-2) which has 1 neutron and tritium(hydrogen-3), which has 2 neutrons. 

5.0Neutrons and Protons

6.0Applications of Neutrons

As a subatomic particle, neutrons are used in a wide range of processes. Some of them are:

• Nuclear Energy: Neutrons are well known for their usage in nuclear fission, a process used for energy generation in nuclear reactors. 
• In nuclear fission, a neutron is bombarded on the nucleus of radioactive elements, usually uranium - 235 or plutonium - 239, which causes it to split into two sister nuclei. This process of split releases a lot of energy that can be used for various purposes.
• In nuclear fusion, the opposite happens, meaning smaller atomic nuclei combine to form a larger nucleus, as in a star’s core. 
• These nuclear energies are sometimes used as nuclear weapons for wars. 
• Medicine: Neutrons also find their usage in medical treatments such as neutron therapy used in cancer treatments used to treat certain types of tumours.
• Material Science: Neutron scattering is used to study the structure of different materials due to their properties to penetrate deep into matter without damaging it. This is useful in material science and chemistry.