Electrons with de-Broglie wavelength $\lambda $ fall on the target an $X-$ ray tube. The cut off wavelength of emitted $X-$ ray is
${\lambda _0} = \frac{{2mc{\lambda ^2}}}{h}$
${\lambda _0} = \frac{{2h}}{{mc}}$
${\lambda _0} = \frac{{2{m^2}{c^2}{\lambda ^3}}}{{{h^2}}}$
${\lambda _0} = \lambda $
In Bohr model of hydrogen atom, the force on the electron depends on the principal quantum number as
If radiation of allow wavelengths from ultraviolet to infrared is passed through hydrogen agas at room temperature, absorption lines will be observed in the :
From kinetic theory, tell the dimension of an atom.
In 1911 , the physicist Ernest Rutherford discovered that atoms have a tiny, dense nucleus by shooting positively charged particles at a very thin gold foil. A key physical property which led Rutherford to use gold was that it was
What radioactive source did the Geiger and Marsden use in the scattering experiment?