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The smallest wavelength of Lyman series is 91 nm. The difference between the largest wavelengths of Paschen and Balmer series is nearly ____ nm. (1) 1875 (2) 1550 (3) 1217 (4) 1784

1. 1875
2. 1550
3. 1217
4. 1784

Correct answer: 1217

Solution

The Lyman, Balmer, and Paschen series correspond to transitions of electrons in a hydrogen atom, with the smallest wavelength in the Lyman series indicating the highest energy transition. The largest wavelengths in the Paschen and Balmer series can be calculated, and their difference yields 1217 nm, which is the correct answer.

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