The problem “Everyone Loves Spectra” is a good introduction to atomic spectroscopy. This simplified example is found to be quite rare in a variety of problems provided in different competitions. That is why it was so frustrating to see that the original problem given in the Baltic chemistry competition included serious mistakes.
Firstly, it was not defined what is Zeff and n. Secondly, “bigger” was mismatched with “lower”. Surprisingly, one student solved the problem absolutely right (defining Zeff to be negative!). Other students were granted points with extra generosity for following the instructions given in the text, even if they got negative value for answer. As it was planned the strongest side of the problem was that one could solve it performing simple calculations as described, without any additional knowledge in spectroscopy.
Obviously, the problem was simplified for the competition. In addition, some ideas about the chemistry of visible may be found at Prof. Dr. Dietrich Zawischa’s page. To see individual spectrum, visit SPECTRA. For more reliable data address NIST “basic atomic spectroscopy data”. These data were used for the problem preparation. If you liked the idea of effective charge, try to find the book of J.E. Huheey “Inorganic chemistry. Principles and reactivity”. В русском переводе Дж. Хьюи “Неорганическая химия. Строение вещества и реакционная способность”.