Electromagnetic Radiation and Quantum Phenomena (AS)

Question 1

Conclusion 1 from the Photoelectric Effect:

For a given metal, no photoelectrons are emitted if the radiation has a ______ below the ______ ______.

Answer 1

Conclusion 1 from the Photoelectric Effect:

For a given metal, no photoelectrons are emitted if the radiation has a (frequency) below the (threshold frequency).

Question 2

Conclusion 2 from the Photoelectric Effect:

The photoelectrons are emitted with a variety of ______ ______, ranging from _______ to a ______ ______.

The value of maximum ______ ______ increases with ______ of the radiation, and is unaffected by the ______ of the radiation.

Answer 2

Conclusion 2 from the Photoelectric Effect:

The photoelectrons are emitted with a variety of (kinetic energies), ranging from (zero) to a (maximum value).

The value of maximum (kinetic energy) increases with (frequency) of the radiation, and is unaffected by the (intensity) of the radiation.

Question 3

Conclusion 3 from the Photoelectric Effect:

The ______of photoelectrons emitted per second is ______ to the ______ of the _______.

Answer 3

Conclusion 3 from the Photoelectric Effect:

The (number) of photoelectrons emitted per second is (proportional) to the (intensity) of the (radiation).

Question 4

What couldn’t the photoelectric effect be explained by?

Answer 4

Wave theory

Question 5

What is the stopping potential in regards to the photoelectric effect?

(Stopping potential is denoted at Vs)

Answer 5

The minimum potential difference required to stop the highest kinetic energy electrons from leaving the metal plate in the photoelectric effect.

Question 6

The stopping potential is the minimum ______ ______ required to stop the highest ______ ______ electrons from leaving the ______ ______ in the photoelectric effect.

Answer 6

The stopping potential is the minimum (potential difference) required to stop the highest (kinetic energy) electrons from leaving the (metal plate) in the photoelectric effect.

Question 7

What is the work function, φ?

Answer 7

The work function is the minimum energy required to remove an electron from a metal’s surface.

Question 8

What is the threshold frequency, f?

Answer 8

​The minimum frequency of photons required for photoelectrons to be emitted from the surface of a metal plate through the photoelectric effect.

It is equal to the metal’s work function divided by Planck’s constant.

f = ​φ/h

Question 9

What is an electronvolt (eV)?

Answer 9

An electronvolt is the kinetic energy carried by an electron after it has been accelerated through a potential difference of 1 volt.

Question 10

An electronvolt (eV) is the ______ ______ carried by an electron after it has been accelerated through a ______ ______ of ______.

Answer 10

An electronvolt (eV) is the (kinetic energy) carried by an electron after it has been accelerated through a (potential difference) of (1 volt).

Question 11

Electrons in atoms exist in ______ ______ ______.

Answer 11

Electrons in atoms exist in (discrete energy levels).