The splitting of spectral lines in an external magnetic field is known as the

Options

A. Stark effect
B. Zeeman effect
C. Bohr effect
D. Sommerfeld effect

Answer

B

Explanation

Zeeman showed that if atoms were placed in a strong magnetic field, additional lines appeared on the spectrum. This is because elliptical orbits can only take up certain orientations with respect to the external field, rather than precessing freely. A single line in the normal spectrum will appear as `(2l +1)` lines if a megnetic field is applied.
The Stark effect describes the splitting of spectral lines in electric field.