Particles and Waves Flashcards
Absolute refractive index
the absolute refractive index (or more simply, the refractive index), n, of a medium is the ratio sinθ1/sinθ2
where θ1 is in a vacuum, and θ2 is in the medium
Angle of incidence
the angle between the incident ray and the normal
Angle of refraction
the angle between the refracted ray and the normal
Atomic mass units (u)
by definition one twelfth of the mass of a carbon-12 nucleus
Atomic number
the number of protons in an atomic nucleus. It is this number that determines the element
Binding energy
the energy needed to split a nucleus into its separate nucleons
Chain reaction
when a nucleus undergoes fission it releases neutrons that can go on to collide with other nuclei, causing further fission reactions. If there is a sufficient concentration of suitable nuclei, the process becomes self-sustaining.
Coherent waves
coherent waves are waves that have the same frequency, speed and have a constant phase relationship
coherent waves are waves that have the same frequency, speed and have a constant phase relationship
part of a spectrometer that is used to produce a parallel beam of light
Critical angle
the maximum value of the angle between the normal and the ray in glass, θ glass, for which refraction can occur
Diffraction
an effect that causes waves to bend as they go past the end of an obstacle or through a small gap in a barrier
Dispersion
the process of splitting up light into its constituent colours
Electromagnetic waves
the spectrum of waves that includes radio, visible light, X-rays etc
Excited state
any atomic energy level higher than the ground state
Fission
the splitting of a large atomic nucleus into smaller fragments, with the resultant release of excess energy
Frequency
the number of complete cycles of a wave passing a given point in a given time, usually per second. Frequency is measured in hertz (Hz) where 1 Hz = 1 wave per second.
Fundamental unit of charge
e; the magnitude of charge carried by one electron or one proton. Equal to 1.60 x 10-19 coulombs
Grating
a transparent slide of glass or plastic that has a very large number of equally-spaced grooves machined on to its surface. Each groove acts as a source for coherent beams of light.
Ground state
the lowest energy level of an atom
Induced fission
the deliberate splitting of a large nucleus caused by the collision of the nucleus with a neutron