If in a gaseous sample of one mole of `H`atoms in the ground state the electron in very `H` atom is excited to the `5th` orbit, then how many spectral lines would appear in its absorption spectrum?

Options

A. `6.022 xx 10^(23)`
B. Infinite
C. Just one
D. Ten

Answer

C

Explanation

Radiation (enegry) is obsorbed if the electron moves from the orbit of smaller principal quantum number to the orbit of higher principal quantum number, whereas the radition (enegry) is emitted if the electron moves from higher orbit to lower orbit. Each spectral line (whether in absorption or emission spectrum) can be associated to the particular transition in the `H` atom. Since the enegry gap between the two orbits `(5th` and`1st`) is identical in every `H` atom, just one transition and, hence, one spectral line appears.