In gold foil experiment number of deflected $\alpha -$ particles at angle $90^o$ is $63$ than number of $\alpha -$ particle deflected at $120^o$ is
In the Rutherford experiment, $\alpha -$ particles are scattered from a nucleus as shown. Out of the four paths, which path is not possible?
The first line in the Lyman series has wavelength $\lambda $. The wavlength of the first line in Balmer series is
To accommodate the view that matter is made up to $5$ elements only, a scientist proposed the following hypothesis; that atoms can have a maximum principal quantum number $n _{\operatorname{man}}$ and no higher. Then, which of the following statements must be true ?
In an atom for the electron to revolve around the nucleus, the necessary centripetal force is obtained from the following force exerted by the nucleus on the electron