HIGHER PHYSICS - Particles and Waves

Flashcards covering vocabulary from a Higher Physics lecture on Particles and Waves, focusing on Wave-Particle Duality, the Standard Model, Forces on Charged Particles, and Nuclear Reactions.

Orders of Magnitude

The range of orders of magnitude of length from the very small (sub-nuclear) to the very large (distance to furthest known celestial objects).

The Standard Model of Fundamental Particles and Interactions

A model describing the fundamental particles and interactions, including evidence for sub-nuclear particles and antimatter.

Fermions

Matter particles, consisting of quarks (6 types) and leptons (electron, muon, tau, together with their neutrinos).

Hadrons

Composite particles made of quarks, including baryons (made of three quarks) and mesons (made of two quarks).

Bosons

Force mediating particles, including photons, W and Z bosons, and gluons.

Beta Decay

First evidence for the neutrino.

Fundamental Particles

Particles that cannot be divided into smaller particles; includes 6 types of quarks and 6 types of leptons in the Standard Model.

Hadrons

Particles made from quarks held together by the strong force.

Baryons

Particles made of three quarks or three antiquarks.

Mesons

Particles made of a quark and an antiquark.

Four Forces Experienced by Particles

Strong (nuclear) force, weak (nuclear) force, gravitational force and electromagnetic force.

Strong (Nuclear) Force

Holds the protons together. Acts over a short range and is stronger than the electrostatic force. Only experienced by quarks.

Gravitational Force

Gravitons are purely theoretical and have not been discovered.

Weak (Nuclear) Force

Involved in radioactive beta decay. Acts over a short range and is weaker than the strong nuclear force. Experienced in quark and lepton interactions.

Electromagnetic Force

Combination of the electrostatic and magnetic forces, has infinite range.

Grand Unification Theory

Scientists are working towards a Grand Unification Theory which will link all the forces into one theory.

Electric Field

A region where a charged particle experiences a force (an electrical force) without being touched.

Potential Difference

The potential difference (V) between 2 points in an electric field is a measure of the work done (W) in moving 1 coulomb of charge between the 2 points.

Magnetic Field

Magnetic fields are produced by moving charges or currents in wires. In a simple bar magnet the magnetic field is generated by electrons orbiting atoms that make up the structure of the magnet.

Charged Particles in Fields

Beams of charged particles experience a deflection by both electric and magnetic fields.

Cyclotron

Ions are injected at a point near the centre. A potential difference between the ‘dee’ shaped electrodes accelerates the particles. A magnetic field causes the particles to move in a circular path.

Linear Accelerator (LINAC)

Charged particles are accelerated in a vacuum pipe through a series of electrodes by an alternating voltage.

Synchrotron

Similar to a linear accelerator, bent into a ring so the charged particles can be given more energy each time they go round. Electromagnets keep the particles in a curved path.

CERN

The European particle physics laboratory, it is near Geneva in Switzerland and was established in 1954

Nuclear Reactions

Nuclear equations to describe radioactive decay and fission and fusion reactions; mass and energy equivalence, including calculations; coolant and containment issues in nuclear fission reactors.

Rutherford's Scattering Experiment

Positively-charged alpha particles were fired at a very thin piece of gold foil.

Model of the Atom - Nucleus

Consists of protons (+ charge) and neutrons (0 charge), so has overall + charge, electrons (- charge) circle around nucleus.

Mass number

The total number of protons plus neutrons in the nucleus.

Atomic number

Represents the number of protons in the nucleus.

Isotopes

Atoms which have the same atomic number but different mass numbers.

Radioactive Decay

Alpha particles, beta particles and gamma rays emitted from atomic nuclei during radioactive decay

Nuclear Fission

A large atomic nucleus splits into 2 smaller nuclei and several neutrons.

Nuclear Fusion

2 small atomic nuclei combine to form a larger nucleus. Other small particles (such as neutrons) may also be formed.

LOST MASS and E = mc2

Reaction where the mass of the products formed is always less than the mass of the starting species - Mass is lost during the reaction.