A neutron is one of the tiny particles that make up the center, or nucleus, of an atom. Every atom has a nucleus made of two types of particles: protons and neutrons packed tightly together. While protons carry a positive electrical charge, neutrons are electrically neutral.

Neutrons play a crucial role in holding atoms together. Without them, the protons in a nucleus would push each other apart because particles with the same charge repel each other. Neutrons act like nuclear glue, helping to bind everything together through the strong nuclear force, one of nature's fundamental forces.

Different versions of the same element can have different numbers of neutrons. For example, all carbon atoms have six protons, but some carbon atoms have six neutrons while others have seven or eight. These variations are called isotopes. Some isotopes are stable, while others are radioactive and break down over time.

Scientists discovered neutrons in 1932, much later than protons and electrons. This discovery helped explain many mysteries about how atoms work and opened the door to nuclear energy and medical treatments. When you hear about nuclear power plants or radiometric dating of ancient fossils, neutrons are central to how those processes work.