Question

a certain transition in the hydrogen spectrum from an excited state to the ground state in one or more steps gives rise to a total of 10 lines how many of of their belong to the visible spectrum​

Answer 1

The number of lines out of the 10 lines that belong to the visible spectrum is equal to 3.

• Let n be the principal quantum number of the excited state.
• The total number of spectral line on transition from nth state to ground state = n(n-1)/2 ⇒ n = 5.
• For a line to belong to the visible spectrum, it mus be a part of the Balmer's series.
• In Balmer's series, transition that takes place from a higher excited state to n=2 are included.
• So, the possible transition lines are 5→2 , 4→2 and 3→2