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WorksheetsP.3.2.2 EM radiation + quantum phenomena
Total questions: 38
Worksheet time: 19mins
The graph shows how the maximum kinetic energy Ek of photoelectrons emitted from a metal surface varies with the reciprocal of the wavelength λ of the incident radiation.
What is the gradient of this graph?
c
h
hc
h/c
Photons of wavelength 290 nm are incident on a metal plate. The work function of the metal is 4.1 eV
What is the maximum kinetic energy of the emitted electrons?
0.19 eV
4.3 eV
6.9 eV
8.4 eV
Which statement suggests that electrons have wave properties?
Electrons are emitted in photoelectric effect experiments.
Electrons are released when atoms are ionised.
Electrons produce dark rings in diffraction experiments.
Electron transitions in atoms produce line spectra.
When light of a certain frequency greater than the threshold frequency of a metal is directed at the metal, photoelectrons are emitted from the surface. The power of the light incident on the metal surface is doubled.
Which row shows the effect on the maximum kinetic energy and the number of photoelectrons emitted per second?
Maximum kinetic energy: remains unchanged
Number of photoelectrons emitted per second: remains unchanged
Maximum kinetic energy: doubles
Number of photoelectrons emitted per second: remains unchanged
Maximum kinetic energy: remains unchanged
Number of photoelectrons emitted per second: doubles
Maximum kinetic energy: doubles
Number of photoelectrons emitted per second: doubles
Line X on the graphs below shows how the maximum kinetic energy of emitted photoelectrons varies with the frequency of incident radiation for a particular metal.
Which graph shows the results for a metal Y that has a higher work function than X?
A beam of light of wavelength λ is incident on a clean metal surface and photoelectrons are emitted. The wavelength of the light is halved but energy incident per second is kept the same.
Which row in the table is correct?
Maximum kinetic energy of the emitted photoelectrons: Increases
Number of photoelectrons emitted per second: Unchanged
Maximum kinetic energy of the emitted photoelectrons: Decreases
Number of photoelectrons emitted per second: Increases
Maximum kinetic energy of the emitted photoelectrons: Increases
Number of photoelectrons emitted per second: Decreases
Maximum kinetic energy of the emitted photoelectrons: Decreases
Number of photoelectrons emitted per second: Unchanged
In an experiment to demonstrate the photoelectric effect, a charged metal plate is illuminated with light from different sources. The plate loses its charge when an ultraviolet light source is used but not when a red light source is used.
What is the reason for this?
The intensity of the red light is too low.
The wavelength of the red light is too short.
The frequency of the red light is too high.
The energy of red light photons is too small.
Electromagnetic radiation incident on a metal surface can cause electrons to be emitted.
Which of the following statements is correct?
Every photon incident on the surface causes an electron to be emitted.
All the emitted electrons have the same energy.
The range of energy of the emitted electrons depends on the intensity of the radiation.
If the incident radiation is of a single frequency, the number of electrons emitted per second increases if the intensity of the radiation increases.
When comparing X-rays with UV radiation, which statement is correct?
X-rays have a lower frequency.
X-rays travel faster in a vacuum.
X-rays do not show diffraction and interference effects.
Using the same element, photoelectrons emitted using X-rays have the greater maximum kinetic energy.
Monochromatic radiation from a source of light (source A) is shone on to a metallic surface and electrons are emitted from the surface. When a second source (source B) is used no electrons are emitted from the metallic surface. Which property of the radiation from source A must be greater than that from source B?
amplitude
frequency
intensity
wavelength
In a photoelectric experiment, light is incident on the metal surface of a photocell. Increasing the intensity of the illumination at the surface leads to an increase in the
work function
minimum frequency at which electrons are emitted
current through the photocell
speed of the electrons
An atom in the inner coating of a fluorescent tube absorbs a photon of ultraviolet radiation. This causes excitation of the atom from its ground state. A photon of visible light is then emitted.
Which energy level diagram represents this process?
The diagram shows an energy-level diagram for a hydrogen atom.
Electrons, each having a kinetic energy of 2.0 × 10–18 J, collide with atoms of hydrogen in their ground state. Photons are emitted when the atoms de-excite.
How many different wavelengths can be observed with incident electrons of this energy?
1
3
6
7
An electron initially at rest is accelerated through a potential difference. It is then brought to rest in a collision, and all of its kinetic energy is converted into a single photon of electromagnetic radiation. Which one of the following quantities is not required to find a value for the wavelength of the photon?
The mass of the electron
The charge on the electron
The velocity of electromagnetic waves
The value of the potential difference
A particle of mass m has a kinetic energy of E.
What is the de Broglie wavelength of this particle?
A
B
C
D
Which row links both the photoelectric effect and electron diffraction to the properties of waves and particles?
A
B
C
D
Electrons moving in a beam have the same de Broglie wavelength as protons in a separate beam moving at a speed of 2.8 × 104 m s–1.
What is the speed of the electrons?
1.5 × 101 m s–1
2.8 × 104 m s–1
1.2 × 106 m s–1
5.1 × 107 m s–1
Which of the following statements about muons is incorrect?
A muon is a lepton.
A muon has a greater mass than an electron.
If a muon and an electron each have the same de Broglie wavelength then they each have the same momentum.
A muon with the same momentum as an electron has a larger kinetic energy than the electron.
Which of the following classes of electromagnetic waves will not ionise neutral atoms?
What is the reason for this?
ultraviolet
X radiation
gamma radiation
microwave
Experiments on which of the following suggested the wave nature of electrons?
electron diffraction by a crystalline material
β− decay
line spectra of atoms
the photoelectric effect
Which graph best shows the relationship between the momentum p and the wavelength λ for photons?
A
B
C
D
Electrons and protons in two beams are travelling at the same speed. The beams are diffracted by objects of the same size.
Which correctly compares the de Broglie wavelength λe of the electrons with the de Broglie wavelength λp of the protons and the width of the diffraction patterns that are produced by these beams?
A
B
C
D
The intensity of a monochromatic light source is increased. Which of the following is correct?
energy of emitted photon: increases
number of photons emitted per second: increases
energy of emitted photon: increases
number of photons emitted per second: unchanged
energy of emitted photon: unchanged
number of photons emitted per second: increases
energy of emitted photon: unchanged
number of photons emitted per second: unchanged
When comparing X-rays with UV radiation, which statement is correct?
X-rays have a lower frequency.
X-rays travel faster in a vacuum.
X-rays do not show diffraction and interference effects.
Using the same element, photoelectrons emitted using X-rays have the greater maximum kinetic energy.
An electron has a kinetic energy E and a de Broglie wavelength λ. The kinetic energy is increased to 4E. What is the new de Broglie wavelength?
λ/4
λ/2
λ
4λ
A proton moving with a speed ν has a de Broglie wavelength λ.
What is the de Broglie wavelength of an alpha particle moving at the same speed ν?
λ/4
λ
2λ
4λ
For which of the following relationships is the quantity y related to the quantity x by the relationship x ∝ 1/y
A
B
C
D
Which one of the graphs best represents the relationship between the energy W of a photon and the frequency f of the radiation?
A
B
C
D
An electron initially at rest is accelerated through a potential difference. It is then brought to rest in a collision, and all of its kinetic energy is converted into a single photon of electromagnetic radiation. Which one of the following quantities is not required to find a value for the wavelength of the photon?
The mass of the electron
The charge on the electron
The velocity of electromagnetic waves
The value of the potential difference
The diagram shows an energy-level diagram for a hydrogen atom.
Electrons, each having a kinetic energy of 2.0 × 10–18 J, collide with atoms of hydrogen in their ground state. Photons are emitted when the atoms de-excite.
How many different wavelengths can be observed with incident electrons of this energy?
1
3
6
7
Which statement suggests that electrons have wave properties?
Electrons are emitted in photoelectric effect experiments.
Electrons are released when atoms are ionised.
Electrons produce dark rings in diffraction experiments.
Electron transitions in atoms produce line spectra.
The diagram shows an energy level diagram for a hydrogen atom.
Electrons with energy 13.0 eV collide with atoms of hydrogen in their ground state.
What is the number of different wavelengths of electromagnetic radiation that could be emitted when the atoms de-excite?
0
3
6
7
The values of the lowest three energy levels in a particular atom are shown in the table.The diagram shows these levels together with the ground state of the atom.
When an electron moves from level 3 to level 1, radiation of frequency 6.2 × 1014 Hz is emitted.
What is the frequency of the radiation emitted when an electron moves from level 2 to level 1?
2.3 × 1014 Hz
3.5 × 1014 Hz
4.6 × 1014 Hz
8.3 × 1014 Hz
The diagram shows the four lowest energy levels for an electron in an atom. P, Q, R and S represent, to scale, the relative energy values of these energy levels.
An electron transition from level R to level Q is accompanied by the emission of a photon of visible light.
Which electron transition would be accompanied by the emission of a photon of infrared radiation?
S to R
S to Q
Q to P
R to P
The diagram gives some of the energy levels of a hydrogen atom.
The transition of an excited hydrogen atom from E3 to E1 causes a photon of visible light to be emitted.
Which transition causes a photon of ultraviolet light to be emitted?
E4 to E3
E3 to E2
E2 to E1
E1 to E0
The diagram drawn to scale shows some of the energy levels of an atom. Transition P results in the emission of a photon of wavelength 4 × 10–7 m.
Which one of the transitions A, B, C, or D could result in the emission of a photon of wavelength 8 × 10–7 m?
A
B
C
D
The diagram shows some of the energy levels for a hydrogen atom.
A free electron of kinetic energy 20.0 × 10–19 J collides with a hydrogen atom in its ground state. The hydrogen atom is excited from its ground state to the first excited state.
The kinetic energy of the free electron after the collision is
1.8 × 10–19 J
3.6 × 10–19 J
5.4 × 10–19 J
16.4 × 10–19 J
The diagram shows some energy levels of an atom.
The transition E3 to E1 corresponds to the emission of visible light.
A transition corresponding to the emission of infrared radiation could be
E1 to E0
E4 to E1
E1 to E2
E3 to E2
