quantum Flashcards
what did wave theory suggest would happen in PE effect
Suggested any frequency of light would emit, as radiation would be continually be absorbed, lage time
increased intensity would liberate Photoelectrons with greater kinetic energies
what did PE effect prove in regards to particle theory
increased intensity liberates greater amount of electrons per second
photons are liberated immediatley, one poton interacvts with single e-
maximum ek is independent of light intensity
increased frequency increases kinetic energy of photos
what is work function
minimum energy of radiation to cause PE emission
what is stopping potential
pd across metal needed to stop photoelectons with maximum ek
equation relating stopping potential and ek
ek = Vs x e
how does a fluorescent tube work
uses excitation
filled with mercury gas
high pd applied which accelerates free e- across tube
collide with mercury atoms
excite e- inside
when they fall back to og level, photon release photons in UV range
fluourescent coating inside tube absorbs UV, excite and de-exxcite
emit visible light range photons
electron volt definition
energy gained when one electron is accelerated through 1v of pd
how to create line spectra
pass light from flourescent tube through diffraction grating or prism
what do the lines in spectra represent
wavelength of light emmited by tube
how are line spectra proof that electrons exist in discrete energy levels
spectrum is not contiuous and only contains discrete values of wavelengths, photon energies emitted correspond to wavelengths
shows electrons in atoms can only transition between discrete energy levels
how to produce absorption spectrum
pass white light through cooled gas
what do differences in black lines in absorption spectra show
possible differences in energy levels
in de broigle wavelenth, what is fringe seperation proportional to
wavelength
what is fringe seperation inversley proportional to
momentum
what is important about the graphite sheet in electron diffraction experiments
gaps between atoms of graphite must be similar size to de broglie wavelenth of electron to observe clear pattern
