3.2.2.4 Wave-particle duality

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.