What is the photoelectric effect?

The emission of electrons from a metal surface when electromagnetic radiation of sufficiently high frequency is incident upon it.

Define threshold frequency in the context of the photoelectric effect.

The minimum frequency of incident radiation required to cause photoelectric emission from a metal surface.

What happens if electromagnetic radiation below the threshold frequency is shone on a metal surface, even at very high intensity?

No photoelectric emission occurs regardless of the intensity of the incident radiation.

In the photon model, how is energy transferred from electromagnetic radiation to electrons in a metal?

Energy is transferred from radiation to electrons in discrete packets called photons.

How many electrons does a single photon interact with during the photoelectric effect?

Each photon interacts with a single electron.

What condition must the photon energy satisfy for an electron to be emitted from a metal surface?

The photon energy must equal or exceed the work function of the metal for emission to occur.

AQA A-Level Physics 7408

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Particles and Radiation

The photoelectric effect

4 things to know
Papers 1 and 3

Overview

Threshold frequency, the work function, the photoelectric equation and stopping potential.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Numbers

What do the terms in hf = φ + Eₖ mean, and what is stopping potential?

Key term

What is the work function, and why does light below the threshold emit nothing?

Process

How do intensity and frequency each affect photoelectric emission?

Key term

Describe how the photoelectric effect can be demonstrated using a zinc plate and an electroscope

Questions from this subtopic

Each one with the model answer underneath.

1
What is the photoelectric effect?
Model answer
The emission of electrons from a metal surface when electromagnetic radiation of sufficiently high frequency is incident upon it.
2
Define threshold frequency in the context of the photoelectric effect.
Model answer
The minimum frequency of incident radiation required to cause photoelectric emission from a metal surface.
3
What happens if electromagnetic radiation below the threshold frequency is shone on a metal surface, even at very high intensity?
Model answer
No photoelectric emission occurs regardless of the intensity of the incident radiation.
4
In the photon model, how is energy transferred from electromagnetic radiation to electrons in a metal?
Model answer
Energy is transferred from radiation to electrons in discrete packets called photons.
5
How many electrons does a single photon interact with during the photoelectric effect?
Model answer
Each photon interacts with a single electron.
6
What condition must the photon energy satisfy for an electron to be emitted from a metal surface?
Model answer
The photon energy must equal or exceed the work function of the metal for emission to occur.

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