PHOTONS AND
ELECTRONS
@STUDYNOTESBYM
, 1. PHOTOELECTRIC EFFECT
Photoelectric effect: the process that occurs when light shines on a metal and
electrons are ejected
Light shines on a specific
metal If the specific light hits a specific
metal with enough energy, electrons
move away from the metal.
-this process can be used to harvest
energy as moving electrons create
current
Significance of the photoelectric effect: it establishes the quantum theory and it
illustrates the particle nature of light
LIGHT
𝑐 = 𝑓𝜆
c: the speed of light in a vacuum. It is constant 3 × 108 𝑚. 𝑠 −1
f: frequency (Hz)
𝜆: 𝑤𝑎𝑣𝑒𝑙𝑒𝑛𝑔𝑡ℎ (𝑚)
ENERGY OF A PHOTON
• A photon is a particle of energy that is a quantum of the electromagnetic field
• They are particles which transmit light
• The energy of a photon is directly proportional to the frequency of light (the higher
the frequency, the higher the energy of the photon)
𝐸 = ℎ𝑓
E: energy
h: plank’s constant (h= 6,67 × 10−34 )
f: frequency/ threshold frequency (Hz)
ELECTRONS
@STUDYNOTESBYM
, 1. PHOTOELECTRIC EFFECT
Photoelectric effect: the process that occurs when light shines on a metal and
electrons are ejected
Light shines on a specific
metal If the specific light hits a specific
metal with enough energy, electrons
move away from the metal.
-this process can be used to harvest
energy as moving electrons create
current
Significance of the photoelectric effect: it establishes the quantum theory and it
illustrates the particle nature of light
LIGHT
𝑐 = 𝑓𝜆
c: the speed of light in a vacuum. It is constant 3 × 108 𝑚. 𝑠 −1
f: frequency (Hz)
𝜆: 𝑤𝑎𝑣𝑒𝑙𝑒𝑛𝑔𝑡ℎ (𝑚)
ENERGY OF A PHOTON
• A photon is a particle of energy that is a quantum of the electromagnetic field
• They are particles which transmit light
• The energy of a photon is directly proportional to the frequency of light (the higher
the frequency, the higher the energy of the photon)
𝐸 = ℎ𝑓
E: energy
h: plank’s constant (h= 6,67 × 10−34 )
f: frequency/ threshold frequency (Hz)
