Question

Electron are accelerated between parallel plates in a tube containing hydrogen gas at ambient temperature. The potential difference across the plates is 12.9 V.

What spectral lines will be visible in the emission spectrum? Make an energy diagram to support your answer.

Answer 1

Ansawer:

Given that:

Electron are accelerated between parallel plates in a tube containing hydrogen gas at ambient temperature. The potential difference across the plates is 12.9 V.

Note that the electron will gain an energy of 12.9 eV after getting accelerated. This electron can jump from ground state (n=1) to n=4 state. It can't jump into n=5 as shown in below diagram. From n=4, the electron jumps back to lower states as shown in the second diagram, thus emitting wavelengths as shown below