The ionisation energy of hydrogen atom is 13.6 eV. Following Bohr's theory, the energy corresponging to a transition between 3rd and 4th orbit is 
(1) 3.40 eV (2) 1.51 eV (3) 0.85 (4) 0.66 eV
The K line obtained for molybdenum (Z = 42) target is 0.71 . Then, the wavelength of the line of copper (Z = 29) is:
(A) 2.14 (B) 1.52
(C) 1.04 (D) 0.71
The ratio of the energies of the hydrogen atom in its first to second excited states is
(1) (2) (3) (4) 4
Energy levels A, B, C of a certain atom correspond to increasing values of energy i.e. If are the wavelengths of the radiation corresponding to the transitions C to B, B to A and C to A respectively, which of the following relation is correct?
In the Rutherford scattering experiment, what will be the correct angle for -scattering for an impact parameter, b = 0?
Atoms having different atomic number as well as different mass number but having same number of neutrons
1. isotopes 2. isobars
3. isotones 4. isodiaphers
Calculate the highest frequency of the emitted photon in the Paschen series of spectral lines of the Hydrogen atom:
The energy of 24.6 eV is required to remove one of the electrons from a neutral helium atom. The energy in (eV) required to remove both the electrons from a neutral helium atom is: