ATM-014 · Atoms and molecules Sample material

The atom in external fields. The Zeeman and Stark effects

The atom in external magnetic and electric fields: level splitting, the normal and anomalous Zeeman effects, the Paschen–Back effect, electron paramagnetic resonance (EPR) and the Stark effect.

Estimated time: 3 h 4 activities

Learning objective

Explain the splitting of atomic levels in a magnetic field into 2J+1 sublevels.
Distinguish the normal and anomalous Zeeman effects, the selection rules and polarization.
Master the physical basis of the Paschen–Back effect and EPR.
Understand the behaviour of an atom in an electric field — the linear and quadratic Stark effects.

Expected outcomes

Can calculate the Zeeman splitting ΔE = g_J μ_B B m_J and Δν, Δλ between line components.
Determines the number of Zeeman components of a given transition and their shifts (via the Landé factor).
Can find the field, frequency or g factor from the EPR resonance condition.
Can estimate the linear Stark splitting of hydrogen and explains why the effect is quadratic for other atoms.

Interactive modelThe Zeeman effect: level splitting

Activities

Lecture
Lecture · 1 h 20 min · required
The atom in external force fields.
Practice · 1 h 20 min · required
The atom in an electric field. The Stark effect
Self-study · 6 h 10 min · optional
Final test
Test · 20 min · required · pass ≥ 70%

Completion conditions

  • Lecture
  • The atom in external force fields.
  • Final test — at least 70%