Wave particle duality

Electrons with a certain kinetic energy pass through a powdered crystalline sample and are incident on a fluorescent screen. The diagram shows a sketch of the diffraction pattern produced. A change is made and this second pattern is produced. Which change could produce the second pattern?

• decreasing the kinetic energy of the electrons

• replacing the electrons with protons with the same kinetic energy

• using a crystalline sample with a wider spacing between its atoms

• moving the screen closer to the crystalline sample

Which row gives evidence for the wave nature of electrons and evidence for the particulate nature of light?

• A

• B

• C

• D

Which particle has the smallest de Broglie wavelength?

• an electron moving at 4 × 10³ m s⁻¹

• 
  a proton moving at 4 × 10³ m s⁻¹

• 
  an electron moving at 8 × 10⁵ m s⁻¹

• 
  a proton moving at 8 × 10⁵ m s⁻¹

A muon and an electron are travelling at the same speed. Which row gives the particle with the greater kinetic energy and the particle with the longer de Broglie wavelength?

• A

• B

• C

• D

A particle has a kinetic energy of E_k and a de Broglie wavelength of λ. What is the de Broglie wavelength when the particle has a kinetic energy of 4E_k?

• A

• B

• C

• D

Which graph shows the variation of momentum p with wavelength λ of a photon?

• A

• B

• C

• D

Evidence of the wave-like properties of electrons is

• the emission of electrons when short-wavelength light falls on a metal surface.

• the movement of electrons in an electric current.

• the diffraction of electrons by a metal crystal.

• the annihilation of an electron with a positron.

A photon of ultraviolet radiation has a frequency of 1.5 × 10¹⁵ Hz. What is the momentum of the photon?

• 
  3.3 × 10^–41 kg m s^–1

• 1.3 × 10^–40 kg m s^–1

• 
  3.3 × 10^–27 kg m s^–1

• 1.3 × 10^–26 kg m s^–1

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