Wave-particle duality

Define the work function of a metal.

The work function of potassium is 2.3 eV.

Potassium emits electrons from its surface when blue light is incident on it. Extremely intense red light produces no electrons.

Explain these observations in terms of photons and their energy.

Light from a laser is incident on some potassium in a vacuum. Electrons are emitted. The wavelength of the light is 320 nm.

Calculate the shortest de Broglie wavelength of the emitted electrons.

What can be deduced from the diffraction of electrons by a thin film of graphite?

A Electrons are leptons.

B Electrons are negatively charged.

C Electrons interact with atoms on a one-to-one basis.

D Electrons travel as waves.

Your answer

The Planck constant h is an important fundamental constant in quantum physics.

Determine the S.I. base units for h.

A researcher is investigating the de Broglie wavelength of charged particles.

The charged particles are accelerated through a potential difference V. The de Broglie wavelength of these particles is then determined by the researcher.

Each particle has mass m and charge q.