Chapter 9
{ electromagnetic waves } Threshold (CUT-OFF) frequency
*read page 105* (f0):
o minimum frequency of incident
Factors of EM waves: radiation at which electrons will be
emitted from a particular metal
1. Transverse o corresponds to a maximum
wavelength
2. Travel through vacuum WORK FUNCTION (Wo):
3. Travel @ 3 x 108 in vacuum o minimum amount of energy needed to
emit an electron from the surface of
4. Obey wave equation a metal
(c = f λ)
5. Carries energy in the form When E of photon > Wo of metal &
of photons Flight> Fo
➢ Photoelectrons = released
electromagnetic spectrum ➢ Energy of photoelectrons =
Ek (kinetic energy)
Photoelectrons = only release from
surface of a metal when Flight
surpasses the Fo of a metal
*if same metal = used, Wo = k*
Speed of light
➢ Look at F (Hz) & λ(m) in textbook C= fλ
{ photoelectric effect } F = frequency (Hz)
λ = wavelength (m)
C = speed of light in a vacuum
* read pg 106 * ➢ Constant = 3 x 108
Definition: Photon energy
o the process that occurs when Elight = transmitted as a photon
light shines on a metal and ➢ Each photon consists of = amount
electrons are ejected of energy called a quantum
o it establishes the quantum ∝
theory & it illustrates
particle nature of light E = hf
= nb bcz establishes quantum theory & E = hc/ λ
illustrates the particle nature of light E = energy of photon (J)
H = Planck’s constant
M = e/f
o 6.6 x 10-34
= H (planck) F = Frequency (Hz)
{ electromagnetic waves } Threshold (CUT-OFF) frequency
*read page 105* (f0):
o minimum frequency of incident
Factors of EM waves: radiation at which electrons will be
emitted from a particular metal
1. Transverse o corresponds to a maximum
wavelength
2. Travel through vacuum WORK FUNCTION (Wo):
3. Travel @ 3 x 108 in vacuum o minimum amount of energy needed to
emit an electron from the surface of
4. Obey wave equation a metal
(c = f λ)
5. Carries energy in the form When E of photon > Wo of metal &
of photons Flight> Fo
➢ Photoelectrons = released
electromagnetic spectrum ➢ Energy of photoelectrons =
Ek (kinetic energy)
Photoelectrons = only release from
surface of a metal when Flight
surpasses the Fo of a metal
*if same metal = used, Wo = k*
Speed of light
➢ Look at F (Hz) & λ(m) in textbook C= fλ
{ photoelectric effect } F = frequency (Hz)
λ = wavelength (m)
C = speed of light in a vacuum
* read pg 106 * ➢ Constant = 3 x 108
Definition: Photon energy
o the process that occurs when Elight = transmitted as a photon
light shines on a metal and ➢ Each photon consists of = amount
electrons are ejected of energy called a quantum
o it establishes the quantum ∝
theory & it illustrates
particle nature of light E = hf
= nb bcz establishes quantum theory & E = hc/ λ
illustrates the particle nature of light E = energy of photon (J)
H = Planck’s constant
M = e/f
o 6.6 x 10-34
= H (planck) F = Frequency (Hz)
