-In an emission spectrum, the limit of convergence at higher frequency corresponds to the first ionization energy

-Trends in first ionization energy across periods account for the existence of main energy levels and sub levels in atoms

- Successive ionization energy data for an element give information that shows relations to electron configurations

-Solving problems using E = hv

-Calculation of the value of the first ionization energy from spectral data which gives the wavelength or frequency of the convergence limit

- Deduction of the group of an element from its successive ionization energy data

-Explanation of the trends and discontinuities in first ionization energy across a period.