Subatomic particles are the things that make up an atom. They are particles that are smaller than an atom. There are many subatomic particles including quarks, leptons, hadrons, bosons, and hadrons just to name a few. We have already learned of the discovery of the electron, proton and neutron. The majority of the other subatomic particles were discovered through experimentation with particle accelerators. Particle accelerators accelerate subatomic particles to nearly the speed of light and smash them into each other. Scientists gather data from these great collisions and try to identify other smaller subatomic particles. The newest subatomic particle to be identified is the Higgs Boson. In 1964 Peter Higgs proposed the theoretical existence of the Higgs Boson and it wasn’t until May 2013 that concrete experimental evidence was obtained to suggest its existence.
This web lesson will focus on the electron, proton and neutron.
Protons and neutrons are similar in their mass. Although their mass is very small, 1.67 x 10-24 g, it is huge compared to the mass of an electron which has a mass of 9.11 x 10-28 g. These numbers are so small that scientists decided to create a brand new unit that would make a little more sense. The created a unit called the Atomic Mass Unit. An atomic mass unit is defined as 1/12 the mass of a neutral carbon atom. Since carbon has exactly 6 protons and 6 neutrons, an atomic mass unit is equal the mass of one proton or one neutron. Since the electron is so small compared to the proton and neutron we can say it has of 0 amu. That’s right, the electron is so small we just say that it basically weighs nothing.
J.J. Thomson discovered that the electron has a negative charge. Ernest Rutherford discovered that the proton has a positive charge. The neutron on the other hand has no charge.