Rutherford’s $\alpha$-particle experiment showed that the atoms have
Proton
Nucleus
Neutron
Electrons
Give a powerful way to determine an upper limit to the size of the electron.
The binding energy of the electron in a hydrogen atom is $13.6\, eV$, the energy required to remove the electron from the first excited state of $Li^{++}$ is ......... $eV$
In the result of the Geiger-Marsden experiment, by which the trajectory of the $\alpha $ -particle can be calculated ?
The first line in the Lyman series has wavelength $\lambda $. The wavlength of the first line in Balmer series is
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