question_answer

The momentum of hydrogen atom when a photon is emitted in a transition from \[{{n}_{i}}=10\]to \[{{n}_{f}}\]  is-

A)          \[\,7\times {{10}^{-27}}\text{ }kg/ms~\]

B)  \[\,7\times {{10}^{27}}\text{ }kg/ms~\]

C)  \[\,3.5\times {{10}^{-27}}\text{ }kg/ms~\]

D)           \[\,3.5\times {{10}^{27}}\text{ }kg/ms~\]