- Sub-atomic Particles
Particles come in many different sizes. Some are so small that they make up atoms.
These very small particles are called sub-atomic particles. They include electrons, protons, and neutrons.
Even these particles are not the smallest possible. Protons and neutrons are made of even smaller particles called quarks.
The study of these tiny particles is known as particle physics. It also includes particles such as photons, which make up light.
- Microscopic Particles
Atoms themselves can also be described as particles.
Molecules, which are made from several atoms joined together, are also treated as particles.
These are known as microscopic particles. Examples include substances such as carbon and water.
- Macroscopic Particles
The idea of particles is also useful in computer models. Modelling every individual atom would be far too complex.
In astronomy, scientists use particle models to study large systems. For example, they can explore where dark matter is found in the Universe, or what happens inside stars when they explode.
Instead of tracking every atom, scientists represent large regions using fewer particles. These are easier to follow over time.
This method is called an n-body simulation, where n means number. The particles used in these models are called macroscopic particles.
This means there is no single thing called a particle. It is a word we use to describe many different kinds of objects, at many different sizes.