Question

an electron of a stationary hydrogen atom passes fromfifth ebergy level to the ground state . the velocity that the atom acquired as a result of photon emission will be​

Answer 1

Wavelength is given by the formula,

$\frac{1}{ \lambda \: } \: = r(\frac{1}{ {ni}^{2} } - \frac{1}{ {nf}^{2} })$

$\frac{1}{ \lambda \: } \: = r( \frac{1}{ {1}^{2} } - \frac{1}{ {5}^{2} })$

$\frac{1}{ \lambda \: } = (\frac{24r}{25})$

We know that, momentum p

$p = \frac{h}{ \lambda}$

$mv = \frac{24hr}{25}$

$v = \frac{24hr}{25m}$

This is the required answer.