Question

What is the maximum number of emission lines obtained when the exited electron of a H atom in n=6 drop to the ground state ?

Answer 1

Number of lines produced when electron from nth shell drops to ground state = n(n-1)/2

Now according to question lines produced when electron drops from 6^th shell to ground state

= 6(6-1) / 2 = 15

These are produced due to following transition

1) 6 to 5 5 to 4 4 to 3 3to 2 2 to 1 => (5 lines)

2) 6 to 4 5 to 3 4 to 2 3 to 1 => (4 lines)

3) 6 to 3 5 to 2 4 to 1 => (3 lines)

4) 6 to 2 5 to 1
​​​​​ => (2 lines)

5) 6 to 1 => (1 lines)