These are the elementary particles, which together make up the Standard Model of particle physics. All of the atoms in the Universe are built using only the electrons and the ‘up’ and ‘down’ quarks. These interact with each other and stick together with the help of gluons and photons.
Gluons transmit what is known as the ‘strong force’ that binds together quarks to make protons and neutrons, the building blocks of atomic nuclei. Photons transmit the electromagnetic force that acts between electrically charged particles, like electrons.
The other particles in the table are also important, but for less evident reasons. For example, around 60 billion electron neutrinos stream through every square centimetre of your body every second. These neutrinos are made inside the Sun, as a by-product of the process that fuses hydrogen into helium. The ‘weak force’ is responsible for this process of nuclear fusion and is transmitted by the W and Z particles.
The particles in the second and third columns of the Standard Model are like heavier copies of those in the first column. The existence of these heavier particles was crucial in governing the behaviour of the Universe shortly after the Big Bang.
- How can an electron be both a particle and a wave?
- What’s the distance from a nucleus to an electron?