question_answer

In a hydrogen atom, if the electron is replaced by a particle which is 200 times heavier but has the same charge, how would its radius change?           

Answer:

                Radius,                 \[r\propto \frac{1}{m}\]                                 When the electron is replaced by a 200 times heavier particle, the radius decreases to \[\frac{1}{200}\]. of the original radius.