A large collection of hydrogen atoms is initially excited to the seventh Bohr orbit. During complete de-excitation, all possible transitions occur in the sample. How many distinct Lyman-series lines can be observed?
Physics · Atomic Structure and X-rays · atomic structure and bohr atomic model
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Question

A large collection of hydrogen atoms is initially excited to the seventh Bohr orbit. During complete de-excitation, all possible transitions occur in the sample. How many distinct Lyman-series lines can be observed?

Physics · Atomic Structure and X-rays · atomic structure and bohr atomic model

G1 Physics · Accepted Answer

Lyman-series photons are produced by transitions ending in the ground state, n = 1. With the highest occupied level n = 7, the possible upper levels that can directly feed the ground state are n = 2, 3, 4, 5, 6 and 7. That gives six distinct Lyman transitions. Hence N = 6.