Particles & Waves Flashcards
Definitions from Higher Physics unit 3
What are the two main catagories of “Fundamental Particles”?
- Fermions (Matter particles)
- Bosons (Force mediating particles)
What are the four Bosons?
- Gluon
- Graviton
- W & Z Boson
- Photon
What is the Boson associated with the “Strong nuclear force”?
Gluon
What is the Boson associated with the “Weak nuclear force”?
W & Z Boson
What is the Boson associated with the “Gravitational force”?
Graviton
What is the Boson associated with the “Electromagnetic force”?
Photon
What is the difference between the Lepons and Quarks?
Leptons can exist by themselves, Quarks can only exist in pairs or groups.
What are the three Leptons?
- Electron
- Muon
- Tau
What are the six Quarks?
- Up
- Down
- Top
- Bottom
- Charm
- Strange
What is the name given to the group of “near-massless” and “zero charge” Fermions?
Neutrinos
What is meant by “Antimatter”?
The opposite of matter. An antimatter particle will have the same mass as its corresponding matter particle, but with the opposite charge.
What is the anti-particle of the Electron?
The Positron
What is the name given to composite particles made of Quarks?
Hadron
What is the name given to a composite particle consisting of 3 quarks?
Baryon
What is the name given to a composite particle consisting of a quark-antiquark pair?
Meson
What is the range of the “Strong nuclear force”?
The size of the nucleus
What is the range of the “Weak nuclear force”?
The size of the nucleus
What is the range of the “Gravitational force”?
Infinite
What is the range of the “Electromagnetic force”?
Infinite
What is emitted in “Alpha decay”?
A particle consisting of 2 protons and 2 neutrons (an alpha particle) is emitted from the atomic nucleus.
What is emitted in “Beta decay”?
A high speed electron (a beta particle) and a neutrino is emited from the atomic nucleus.
What is emitted in “Gamma decay”?
A high energy photon of electromagnetic radiation (a gamma ray) is emitted from thr atomic nulceus.
What is meant by “Ionisation”?
When one of the three types of radiation is incident (hits) another atom, the radiation can cause ionisation, which removes an outer electron from the nucleus, creating an ion.
What is meant by “Potential difference”?
The work done in moving a unit positve charge between two points.
What is meant by “Electron flow” in terms of current?
The flow of negatively charged electrons. The correct way for current to flow in Scotland, and what is actually happening in a circuit.
What is meant by “Conventional flow” in terms of current?
The flow of positive charges. Tradiionally taught in all English speaking regions apart from Scotland. Not what is actaully happening in a circuit.
Which type of current flow applies to “Fleming’s right hand” rule?
Electron flow (negative charge)
Which type of current flow applies to “Fleming’s left hand” rule?
Conventional flow (positive charge)
What does a “dot” represent in terms of a magnetic field direction?
Field direction is “out of page”.
What does a “cross” represent in terms of a magnetic field direction?
Field direction in “into the page”.
What is meant by the “Atomic number” of an atom?
Number of Protons within the atomic nucleus.
What is meant by the “Mass number” of an atom?
Number of Protons & Neutrons within the atomic nucleus.
How does a “GM tube and counter” work to detect radiation?
When radiation enters through the thin Mica window, the radiation ionises the gas within the tube. These ions allow a current to flow between the casing and the central electrode, which is registered by the counting circuit.
How does a “Cloud Chamber” work to detect radiation?
When radiation passes through the vapour, atoms in the vapour become ionised. The ionised vapour acts as condensation nuclei and
droplets form in the air along the path the radiation took.
What is meant by “Fission”?
A large nucleus splitting into two or more smaller nuclei, releasing energy.
What is meant by “Fusion”?
Two small nuclei join together to make a larger nucleus, releasing energy.
What is meant by “Spontaneous fission”?
Fission that occurs randomly in a radioactive material.
What is meant by “Stimulated fission”?
Fission that occurs due an interaction with a neutron.
What is name of a Hydrogen isotope consisting of 1 proton only?
Hydrogen
What is name of a Hydrogen isotope consisting of 1 proton + 1 neutron?
Deuterium
What is name of a Hydrogen isotope consisting of 1 proton + 2 neutrons?
Tritium
Why is “mass lost” in fission and fusion reactions?
The lost mass has been converted to energy.
What is meant by a “Transverse wave”?
A wave in which the medium oscillates at right angles to the wave motion.
What is meant by a “Longitudinal wave”?
A wave in which the medium oscillates at parallel to the wave motion.
What is meant by the “Normal line” in an optics diagram?
Dashed line at 90 degrees to the surface, where all angles are measured from.
What is meant by the “Incident ray” in an optics diagram?
The ray of light ‘hitting’ the surface in question
What is meant by the “Reflected ray” in an optics diagram?
The ray of light that has undergone reflection
What is meant by the “Refracted ray” in an optics diagram?
The ray of light that has undergone refraction
What is meant by the “Angle of incidence”?
The angle between the normal and the incident ray.
What is meant by the “Angle of Reflection”?
The angle between the normal and the reflected ray.
What is meant by the “Angle of Refraction”?
The angle between the normal and the refracted ray.
What is meant by “Refraction”?
The process by which a ray of light changes speed as it moves between materials of different refractive index.
What is meant by the “critical angle”?
The angle of incidence at which the angle of refraction is at 90° to the normal.
What is the condition for “Refraction” in terms of angle of incidence?
Angle of incidence less than the critical angle.
What is the condition for “Total internal reflection” in terms of angle of incidence?
Angle of incidence greater than the critical angle.
What is meant by the “Irradiance” of a source of light?
The light energy incident on every square metre of a surface per second or more simply power per square metre.
What are the assumptions made in order to apply the inverse square law to irradiance of a light source?
- Light source is a point source of light.
- Light source emited equally in all directions.
- There is no reflections from surfaces etc.
Give a piece of experimental evidence of light acting as a wave.
The interference of light in Young’s double slit experiment.
Give a piece of experimental evidence of light acting as a particle.
The emission of photoelectrons due to high frequency incident radiation in the Photoelectric effect.
What is meant by the “Work function” of a material?
The minimum energy which must be supplied per photon to enable an electron to escape from the metal surface.
What is meant by the “Threshold frquency”?
The minimum frequency of a photon which when indicent on an metal would aloow the photoemission of an electron.
How can the threshold frequency of a Photon be found from a graph of freqency vs energy.
The X-intercept.
What is a Continuous Spectrum?
Light, when seen through a prism or diffraction grating, shows all wavelengths of visible light.
What is a “Line” Spectrum?
Light, when seen through a prism or diffraction grating, shows only a specific set of wavelengths of visible light.
What is meant by a “Line Absorbion spectrum”?
A spectrum with certain frequencies have been absorbed in the Sun’s outer atmosphere, leaving dark gaps in the spectrum.
What is meant by a “Line Emission spectrum”?
A spectrum showing only certain frequencies, which correspond to energy transitions within the atoms of that element.
What type of electron transition causes the “gaps” in a line absorbion spectrum?
A transition from a low energy level to a higher energy level. Caused by the absorbion of a photon with energy matching the transiton.
What type of electron transition causes the “bright lines” in a line emission spectrum?
A transition from a high energy level to a lower energy level. Caused by the emission of a photon with energy matching the transiton.
