Question

What is Stark Effect?

Answer 1

1. The Stark effect occurs when an external electric field causes the spectral lines of atoms and molecules to shift and split.
2. Johannes Stark, a German scientist, discovered this phenomenon.
3. In a positive-ray tube, Stark saw the hydrogen spectrum released right beyond the perforated cathode.
4. He was able to establish a strong electric field in a few millimeters by placing a second charged electrode parallel and near to the cathode.
5. Stark observed with a spectroscope that the characteristic spectral lines of hydrogen, known as Balmer lines, were split into a number of symmetrically spaced components, some of which were linearly polarised (vibrating in one plane) with the electric vector parallel to the lines of force, and the balance was polarised perpendicular to the field direction except when viewed along the field.