Spectrum of the hydrogen atom

Measure a part of the hydrogen atom spectrum and distinguish it from the spectrum of deuterium.

Questions

  1. A series of lines in the spectrum of atomic hydrogen lie at 656.46 nm, 486.27 nm, 434.17 nm and 410.29 nm. What is the wavelength of the next line in the series? What is the ionization energy of the atom when its electron is in the lowest state ?
  2. Calculate the mass of the deuteron given that the first line in the Lyman series of H lies at 82 259.098 cm-1 whereas that of D lies at 82281.476 cm-1. Calculate the ratio of the ionization energies of H and D.
  3. Positronium consists of an electron and a positron (same mass, opposite charge) orbiting around a common center of mass. The broad features of the spectrum are therefore expected to be hydrogen-like with the differences arising largely from differences in mass. Predict the wavenumbers of the first three lines of the Balmer series of positronium. What is the ionization energy of positronium?
  4. Is it possible to resolve the isotopic splitting of a Balmer line using a monochromator that has the following parameters: f = 0.1 m, grating of 1200 groves/mm, grating size of 60 mm, and slits of 100 µm?