AL chem (convergence limit)

Similar method CANNOT be used to determine the ionization enthalpy of elements other than hydrogen.

In a hydrogen atom, there is only one energy level for each quantum number n. In other words, all subshells in the same electronic shells are in the same energy level.

For atoms other than hydrogen, different subshells in the same shell have different energy levels. For example, the 2s and 2p subshells of a sodium atom are in different energy levels. Therefore, the emission spectra of other elements are complicated. Unlike hydrogen emission spectrum, the emission spectra of other elements are complicated, and it is impossible to find distinct series of spectrum lines in their emission spectra. Due to the absence of distinct series of spectrum lines, it is impossible to find the ionization enthalpy from the convergence limit of a distinct series.
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The emission spectrum is formed when excited electrons fall from a higher energy level to a lower energy level.
An emission spectrum consists of discrete lines, showing that energy levels and energy released is quantized.
In Lyman series, electrons at higher energy levels drop to n = 1 level and emit photons with wavelength in the UV region.
In Balmer series, electrons at higher energy level drop to n = 2 level and emit photons in the visible light region.
In Paschen series, electrons drop to n = 3 level and emit photons with wavelength in the infra-red region.
Ionization energy can be found by the convergence limit.




If elecctrons of element you use can release energy from higher energy levels to n = 1 level, then the lines of emission spectrum of this element can be found in Lyman series. As you know, there are 2 element in 2s orbital which are H and He. To sum up, it can determine the ionizaton enthalpy of H and He.

Sodium has the convergence limit from n=3 to n=∞.