Chemistry · Atomic Structure

In the Zeeman effect, magnetic field causes the electrons in an atom to have different energies, depending on their orientation in the field. This results in the splitting of the spectral lines into multiple components. 

This effect is named after the Dutch physicist Pieter Zeeman, who discovered it in 1896. 

Stark effect is the splitting of spectral lines in the presence of an electric field. Hence, this option is incorrect.

In the Zeeman effect, the magnetic field causes the electrons in an atom to have different energies, depending on their orientation in the field. This results in the splitting of the spectral lines into multiple components. This option is therefore correct.

Aufbau principle is a rule that states: "Electrons fill the lowest energy orbitals first before moving to the higher energy orbitals." Hence, this option is incorrect.

Pauli's Exclusion Principle is a fundamental concept in quantum mechanics and atomic physics, and it can be stated as : "No two electrons in an atom can have the same four quantum numbers". Hence, this option is incorrect.