In a hydrogen sample, if the atoms are excited to states with principal, quantum number 20, then the number of different wavelengths which may be observed in the spectrum is

Options

A. 100
B. 140
C. 190
D. 230

Answer

C

Explanation

When atom are excited from ground state to excited state with `n =20,` then number of spectral line possible are
`= (m (n-1))/(2)` [where, n= principal quantum number]
`(20(20-1))/(2) =190`