electromagnetic radiation - aka radiant energy
- visible light is a type of electronmagnetic radiation
- speed of light = 3.00 x 108 m/s
- wavelength - distance between successive peaks/troughs
- frequency - # of complete wavelengths/cycles that pass a point per second
- amplitude - intensity of radiation; max height of wave
- (frequency)(wavelength) = speed of light = c = nl
- frequency = n
- wavelength = l
- smaller wavelength >> higher frequency >> more powerful radiation
Planck's constant - 6.63 x 10-34 J-s
- quantum - "fixed amount;" smallest quantity of energy that can be emitted/absorbed
- energy always emitted in chunks of minimum size
- energy = Planck's constant x frequency
- E = hn
- energy quantized, can only increase in steps (though steps are extremely small)
- photoelectric effect - photons striking metals cause electrons to be emitted
- photon - energy packet, transfers energy to electrons
- energy of photon = E = hn
- 6.02 x 1023 photons per mol
Find energy of 1 photon light w/ wavelength 589 nm
- c = nl
- 3.00 x 108 m/s = n(589 nm)
- n = (3.00 x 108 m/s) / (5.89 x 10-7 m) = 5.09 x 1014 s-1
- E = hn
- E = (6.63 x 10-34 J-s)(5.09 x 1014 s-1) = 3.37 x 10-19 J/photon
Subject:
Subject X2:
