2.4

Question 1

What is photoemission?

Answer 1

Photons of a sufficient energy can eject electrons from the surface of certain materials. This is called the photoelectric effect.

Question 2

What does the photoelectric effect show about the nature of light?

Answer 2

evidence of the particle model of light

Question 3

What is a photon?

Answer 3

A fundamental particle that carries electromagnetic force, or in simpler terms, a light particle.

Question 4

How does the energy of a photon relate to its frequency?

Answer 4

The higher the energy of a photon, the higher the frequency.

Question 5

Break down the equation E = hf

Answer 5

E = energy (J)
h = Planck’s constant (6.63x10^-34)
f = frequency (Hz)

Question 6

What is threshold frequency?

Answer 6

The minimum frequency required to cause photoemission

Question 7

What is the work function?

Answer 7

The minimum energy required to remove an electron from a material (photoemission)

Question 8

Give an equation that shows the relationship between work function and threshold frequency

Answer 8

W = hf
o

W = work function (J)
h = Planck’s Constant (Js)
f = threshold frequency (Hz)

Question 9

How do you calculate the kinetic energy of a photon?

Answer 9

Ek = E - W

Ek = kinetic energy (J)
E = energy of photon (J)
W = work function (J)

Question 10

Given that the work function is related to threshold frequency, give another ways that this equation can be written

Answer 10

Ek = hf - h(fo)

Ek = kinetic energy (J)
h = Planck’s constant (Js)
f = frequency of photon (Hz)
fo = threshold frequency (Hz)