3 Quantum Phenomena Flashcards
wave-particle duality
wave like = diffraction
particle like = photoelectric effect
line spectra
absorption spectrum
black lines are correct wavelengths
electron excites
absorbed
line spectra
emission spectrum
photon gives off a frequency as a colour
Fluorescent lamp
ionisation and exciation of the mercury atoms occur as they collide with each other (electrons)
mercury atoms emit UV photons
photons absorbed by fluorescent coating causing exication of atoms
coating atoms dexcitation in steps and emit visible photons
excitation
absorbs energy with becoming ionized
if the photon doesn’t have the full amount of energy then nothing would happen
extra energy turns to kinetic energy
de-excitation
photons given out
threshold frequency
minimum frequency of incident light which can cause the photoelectric effect
photoelectric effect
1 electron absorbs 1 photon
UV light photon have enough to free an electron
photoelectricity
electroscope
zinc and gold leaf
both negative
repel
wavelength
least distance between two adjacent vibrating particles with the same displacement and velocity at the same time
work function
minimum amount of energy needed by an electron to escape from a metal surface
ionisation
process of creating ions
ion
charged atom
electron volt
amount of energy equal to 1.6*10-16 J defined as the work done when an electron is moved by 1V
fluorescence
glow of light from a substance exposed to ultraviolet radiation, the atomised-excite in stages and emit visible photons in the process
ground state
lowest energy state of an atom
energy levels
the energy of an electron in an electron shell of an atom
diffraction
spreading of waves on passing through a gap or near an edge
de Broglie
matter particles have a wave-like nature characterised by the de Broglie wavelength
λ = h / mv
cloud chamber
sealed environment of supersaturated vapour of water or alcohol
a charged particle interacts with the mixture- the fluid is ionised and becomes a mist
particle accelerator explaination
uses electromagnetic field to propel charged particles to nearly light speed and to contain them in beams
radioscope / ion ion implanters
particle accelerator stanford linear accelerate
california
3km
50000 million volts
particle accelerator harden collider
geneva
accelerate charged particle to energies ,ore than 7000GeV
27km
Stopping potential
Stopping potential is defined as the potential necessary to stop any electron
Would have to impose an electric field is that it will make it loss the extractly amount of kinetic energy
Electron diffraction
Suggest that particles posses wavelike properties
