The Photoelectric Effect Alternate E-day Project

Instructions

You have one E-day session to complete this project.

Work your way through this project, reading the slides and answering the questions.

REVISION OF EM WAVES
Watch the embedded video below. If you have issues playing it within Formative, you can watch it on You Tube using this link

Required

1

The electric and magnetic fields in electromagnetic waves are oriented

Required

1

Which measures the number of waves that pass a certain point per second?

Required

1

What happens to wavelength if the frequency of a wave doubles?

Required

1

Which type of wave has the longest wavelength?

Required

1

What is the relationship between the frequency and energy of a wave?

Required

1

What defines the colour of light within the visible spectrum?

Copy this worked example into your workbook

3

Please upload a scanned copy of the Worked example table in your workbook, proving you have copied it into your book.

THE PHOTOELECTRIC EFFECT

Required

1

What is the photoelectric effect?

Required

1

In the photoelectric effect ....

Required

1

Who proposed the concept of 'quantum' in physics?

Required

1

What is the term for the smallest discrete amount of any physical quantity?

Required

2

What is the wavelength and frequency of UV light with energy of 3,74 x 10−18 J?

Required

1

The photoelectric effect supports the particle theory of light because:

Required

1

Which scientist initially explained the photoelectric effect?

Required

1

Which photon is more energetic: A red one or a violet one?

Required

1

What does 'threshold frequency' signify in the context of the photoelectric effect?

Required

1

What does the 'work function' represent in the context of the photoelectric effect?

Watch this short video on the photoelectric effect.
You can also watch it on You Tube by clicking this link (first 2:43 min)

Look at what happens when light of various frequencies is shone onto a metal.

Required

1

What happens if the frequency of light is below the threshold frequency?

Required

1

According to the photoelectric effect, what determines the kinetic energy of the ejected electrons?

Required

1

Which factor does NOT affect the number of electrons emitted in the photoelectric effect?

Required

6

Increasing the ______________ of the light, increases the energy of the photon.
Increasing the ______________  of the light, increases the number of photons emitted.
If the frequency of light is ______________ the threshold frequency, then no electrons are emitted.
If the frequency of light is  _____________  the threshold frequency, then electrons will be emitted with zero kinetic energy.
If the frequency of light is _________________   the threshold frequency, then electrons will be emitted with kinetic energy.
This kinetic energy value is equal to the energy of a photon minus the __________________ of the metal.

Other Answer Choices:

threshold frequency

intensity

equal to

energy

less than

frequency

work function

greater than

5

The table below shows the work function (in electron volts) of various metals.
QUESTION: Will the photoelectric effect be observed when light of 710 nm is shone onto the surface of potassium?
ALL OF THESE ANSWERS MUST BE TYPED IN SCIENTIFIC NOTATION
Type the answers for each of these using this as an example: 9,22 x 10-12 should be typed as 9,22 x 10^-12
Step 1: Convert the work function W0  from eV to Joules. Answer: W0 = _______ J.
Step 2: Calculate the threshold frequency f0 of potassium using W0 =hf0. Answer: f0 = _______ Hz.
Step 3: Calculate the frequency of the light using its wavelength. f = _______ Hz.
Step 4: Compare the frequency of the light to the threshold frequency f0. The threshold frequency f0 is _______ (greater than/less than/equal to) the frequency of this light.
Step 5: Therefore, the photoelectric effect _______ (will/will not) be observed.

5

The table below shows the work function (in electron volts) of various metals.
QUESTION: Will the photoelectric effect be observed when light of 710 nm is shone onto the surface of aluminium?
ALL OF THESE ANSWERS MUST BE TYPED IN SCIENTIFIC NOTATION
Type the answers for each of these using this as an example: 9,22 x 10-12 should be typed as 9,22 x 10^-12
Step 1: Convert the work function W0  from eV to Joules. Answer: W0 = _______ J.
Step 2: Calculate the threshold frequency f0 of aluminium using W0 =hf0. Answer: f0 = _______ Hz.
Step 3: Calculate the frequency of the light using its wavelength. f = _______ Hz.
Step 4: Compare the frequency of the light to the threshold frequency f0. The threshold frequency f0 is _______ (greater than/less than/equal to) the frequency of this light.
Step 5: Therefore, the photoelectric effect _______ (will/will not) be observed.

4

Now use the complete photoelectric equation to calculate the maximum velocity of ejected electrons when light of 310 nm is shone onto the surface of sodium, which has a work function of 2,3 eV.

ALL OF THESE ANSWERS MUST BE TYPED IN SCIENTIFIC NOTATION
Type the answers for each of these using this as an example: 9,22 x 10-12 should be typed as 9,22 x 10^-12

E = _______ J
W0 = _______ J
EK = _______ J
∴ 𝓋 = _______ m.s-1

Consider the following photoelectric effect graph obtained for two metals P and Q.

ANSWERS MUST BE TYPED IN SCIENTIFIC NOTATION WHERE APPLICABLE.
Type the answers for each of these using this as an example: 9,22 x 10-12 should be typed as 9,22 x 10^-12

Required

1

Required

1

Required

1

Calculate the work function of Q.

4

Consider the following graph obtained using data from an investigation of the photoelectric effect.
ANSWERS MUST BE TYPED IN SCIENTIFIC NOTATION WHERE APPLICABLE.
Type the answers for each of these using this as an example: 9,22 x 10-12 should be typed as 9,22 x 10^-12

Write the values of :
Work function = _______ eV 
Threshold frequency = _______ Hz
Gradient of graph = _______ J.s    which represents _______ constant.

	wavelength (m)	frequency (Hz)
3,62 × 1014
5,67 × 1015
5,29 × 10−8
1,10 × 10−20

	wavelength (m)	frequency (Hz)
3,62 × 1014
5,67 × 1015
5,29 × 10−8
1,10 × 10−20

The Photoelectric Effect Alternate E-day Project

REVISION OF EM WAVES

The electric and magnetic fields in electromagnetic waves are oriented

Which measures the number of waves that pass a certain point per second?

What happens to wavelength if the frequency of a wave doubles?

Which type of wave has the longest wavelength?

What is the relationship between the frequency and energy of a wave?

What defines the colour of light within the visible spectrum?

Please upload a scanned copy of the Worked example table in your workbook, proving you have copied it into your book.

THE PHOTOELECTRIC EFFECT

What is the photoelectric effect?

In the photoelectric effect ....

Who proposed the concept of 'quantum' in physics?

What is the term for the smallest discrete amount of any physical quantity?

What is the wavelength and frequency of UV light with energy of 3,74 x 10−18 J?

The photoelectric effect supports the particle theory of light because:

Which scientist initially explained the photoelectric effect?

Which photon is more energetic: A red one or a violet one?

What does 'threshold frequency' signify in the context of the photoelectric effect?

What does the 'work function' represent in the context of the photoelectric effect?

What happens if the frequency of light is below the threshold frequency?

According to the photoelectric effect, what determines the kinetic energy of the ejected electrons?

Which factor does NOT affect the number of electrons emitted in the photoelectric effect?

Calculate the work function of Q.

REVISION OF EM WAVES

The electric and magnetic fields in electromagnetic waves are oriented

Which measures the number of waves that pass a certain point per second?

What happens to wavelength if the frequency of a wave doubles?

Which type of wave has the longest wavelength?

What is the relationship between the frequency and energy of a wave?

What defines the colour of light within the visible spectrum?

Please upload a scanned copy of the Worked example table in your workbook, proving you have copied it into your book.

THE PHOTOELECTRIC EFFECT

What is the photoelectric effect?

In the photoelectric effect ....

Who proposed the concept of 'quantum' in physics?

What is the term for the smallest discrete amount of any physical quantity?

What is the wavelength and frequency of UV light with energy of 3,74 x 10−18 J?

The photoelectric effect supports the particle theory of light because:

Which scientist initially explained the photoelectric effect?

Which photon is more energetic: A red one or a violet one?

What does 'threshold frequency' signify in the context of the photoelectric effect?

What does the 'work function' represent in the context of the photoelectric effect?

What happens if the frequency of light is below the threshold frequency?

According to the photoelectric effect, what determines the kinetic energy of the ejected electrons?

Which factor does NOT affect the number of electrons emitted in the photoelectric effect?

Which metal has the highest threshold frequency?

Which metal has the greatest work function?

Calculate the work function of Q.

Which metal has the highest threshold frequency?

Which metal has the greatest work function?