7.2 the nature of matter Flashcards
what is planck‘s constant
6.626 x 10 to the -34
what is the formula relating placks constant and energy
delta E = nhv
n = integer
v = frequency of the electromagnetic radiation absorbed or emmited
energy can be lost for integer values of hv
what is a photon
- a piece of enegie
- they are quantized, travel in discrete units, not long wavelenghts, discrete little particles
- they hAVE FIXED ENERGY, QUANTIZED
- not a particle, but acts like one
= E photon = (h)(f)
what are the main principles of the photoelectric effect?
When piece of metal is bombarded with electrons:
- no electrons are emited below a specific threshold frequency
- light with frequency lower than threshold frequency will not emmit electrons regardless of the intensity of the light
- for light greater than threshold, num of electrons emitied increases with intensity of the light
- kinetic energy of emited electrons also increases linearly with intensity of the light
what is the nuane with the mass of a photon
Photon‘s do not actually have a mass, they have an apparent mass, can act as if they have a mass
what is an interferrance pattern (diffraction)
when 2 disturbances occur near one another, and their respective series of waves overlap
what is constructive interference
resulting wave is bigger than original waves
what is destructive interference
resulting wave has an amplitude of 0
for periodic waves how is there a constructive interference, what does it produce
when the waves of in phase, alined
produces a bright spot
for periodic waves how is there a destructive interference, what does it produce
when the waves are out of phase, (the through of one wave is over the pick of the other) , produces a dark spot