Particle Physics Brief but almost complete Strong Nuclear

Particle Physics Brief but almost complete

Strong Nuclear Force • The strong nuclear force is one of the 4 natural forces of nature which keep the neutrons and protons together in the nucleus • This force overcomes the Coulomb force (which repels like charges) when the distance between them is VERY small (r < 10^-15 m) • This happens because the particles that make up protons and neutrons are attracted to each other. These particles are called quarks.

Weak Nuclear Force • The weak nuclear force is responsible for radioactive decay – when neutrons or protons change into each other by releasing an electron or positron as well as some type of neutrino. • This reaction is called Beta decay. An electron/positron is released along with a neutrino/anti neutrino depending on the reaction

Beta Decay • β- decay – a neutron turns into a proton, releasing an antineutrino and an electron • β+ decay – a proton turns into a neutron, releasing a neutrino and a positron • The β particle is the electron/positron. This is where we get β rays from

Quarks • There are 6 types of quarks, they make up hadrons, which are protons and neutrons. 3 quarks make one hadron. • We discovered quarks by using nuclear atomic colliders, which cracks open atoms and their protons/neutrons to release quarks • The strong nuclear force keeps quarks together to make hadrons

Quarks • Video on quarks

Fermions • A fermion is defined as any particle with their spin number = ½ • These would include electrons, positrons, quarks, and neutrinos • A positron is a positive electron. • A neutrino is a very tiny particle that is produced from nuclear reactions, they are very hard to detect

Fermions • Video on neutrinos

Nuclear Energy • Nuclear fusion – joining two atomic nuclei which can release or absorb energy depending on the reaction • Nuclear fission – splitting an atom into two atoms, which can also release or absorb energy depending on the reaction • Stars get energy from nuclear fusion

The Photoelectric Effect • The photoelectric effect is when you shine a light of a specific frequency on a sheet of one element (gold for example). If the light is the right frequency, so that it has a particular energy, it can force the atoms to release electrons, making electricity • Einstein showed mathematically how the photoelectric effect worked, which was huge for quantum theory.

The Photoelectric Effect • Video on the photoelectric effect

Particle Physics • Just a worksheet with questions that may show up on the final