Question

What is the maximum number of emission lines obtained when the excited electron of a hydrogen atom in $n=5$ drops to the ground state?

• A. 10
• B. 5
• C. 12
• D. 15

Answer 1

Answer: (A)

10

Answer 2

Number of spectral lines obtained when an electron drops from $n t h$ level to ground level $=\frac{n(n-1)}{2}$
$\therefore$ Number of emission lines obtained, when electron drops from $5th$ level to ground state
$=\frac{5(5-1)}{2}=\frac{5 \times 4}{2}=10$