Which of the following transitions in hydrogen atoms emit photons of highest frequency?
n = 2 to n = 6
n = 6 to n = 2
n = 2 to n =1
n = 2 to n =1
The energy spectrum of β-particles [number N(E) as a function of β-energy E] emitted from a radioactive source is
The diagram shows the energy levels for an electron in a certain atom. Which transition shown represents the emission of a photon with the most energy?
lll
IV
I
I
An electron from various excited states of hydrogen atom emits radiation to come to the ground state. Let λn, λg, be the de Broglie wavelength of the electron in the nth state and the ground state respectively. Let Λn be the wavelength of the emitted photon in the transition from the nth state to the ground state. For large n, (A, B are constants)
If the series limit frequency of the Lyman series is vL, then the series limit frequency of the Pfund series is:
vL/25
25vL
16 vL
vL/16
A.
vL/25
Series limit frequency of the Lyman series is given by
Series limit frequency of the Pfund series
What wavelength must electromagnetic radiation have if a photon in the beam has the same momentum as an electron moving with a speed 1.1 x 105 m/s (Planck's constant = 6.6 x 10-34 J-s, rest mass of electron = 9 x 10-31 kg ?
2/3 nm
20/3 nm
4/3 nm
40/3 nm
An electron, a neutron and an alpha particle have same kinetic energy and their de-Broglie wavelength are λe, λn, λα and respectively. Which statement is correct about their de-Broglie wavelengths ?
λe > λn > λα
λe < λn > λα
λe < λn < λα
λe > λn < λα
An electron of mass me and a proton of mass mp are accelerated through the same potential. Then, the ratio of their de-Broglie wavelengths is
1
The significant result deduced from the Rutherford's scattering experiment is that
whole of the positive charge is concentrated at the centre of atom
there are neutrons inside the nucleus
α-particles are helium nuclei
electrons are embedded in the atom
The de-Broglie wavelength and kinetic energy of a particle is 2000 and 1 eV respectively. If its kinetic energy becomes 1 MeV, then its de-Broglie wavelength is