Fermion facts for kids
A fermion is a type of tiny particle. These particles are super small and light. Think of them as the basic building blocks of everything around you. For example, atoms are made up of fermions! A famous scientist named Paul Dirac gave them their name to honor another great scientist, Enrico Fermi.
An electron is a fermion, but a photon (a particle of light) is not.
Contents
What Makes Fermions Special?
Spin and the Pauli Exclusion Principle
One special thing about fermions is their "spin" number. It's always a half-number, like 1/2, 3/2, or 5/2. Because of this, fermions follow a rule called the Pauli exclusion principle. This rule says that no two fermions can be in the exact same place at the same time if they have the same properties. It's like saying two students can't sit in the same chair at the same time! This means fermions can bump into each other.
Fermions vs. Bosons
This behavior is different from another group of tiny particles called bosons. Many bosons, like photons, can be in the same place at the same time. Fermions, however, need their own "space" if their properties are the same.
Types of Fermions
Most well-known fermions have a spin of 1/2. An electron is an example of a fermion with a spin of 1/2. Electrons belong to a group of fermions called leptons.
Fundamental Fermions
Fundamental fermions are particles that are not made up of anything smaller. There are two main types of fundamental fermions:
There are 6 different types of quarks and 6 different types of leptons. Scientists call these different types "flavors."
- Quarks: up, down, charm, strange, top, bottom
- Leptons: electron, muon, tau, electron neutrino, muon neutrino, tau neutrino
Antimatter Partners
Each of these fermions also has an anti-particle that goes with it. This means there are a total of 24 different fundamental fermions! An anti-particle is very similar to its regular particle, but it has the opposite electrical charge.
For example:
- The "up," "charm," and "top" quarks have an electrical charge of +2/3. Their anti-particles (anti-up, anti-charm, anti-top) have a charge of -2/3.
- The "down," "strange," and "bottom" quarks have a charge of -1/3. Their anti-particles have a charge of +1/3.
- The electron, muon, and tau leptons all have a charge of -1. Their anti-particles (like the anti-electron, also called a "positron") have a charge of +1.
- All the neutrinos and anti-neutrinos have a charge of 0.
The main difference between quarks or leptons that have the same charge is their mass.
See also
In Spanish: Fermión para niños
