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प्रश्न
State any two limitations of Bohr’s model for the hydrogen atoms.
State any one limitation of Bohr’s theory of hydrogen atom.
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उत्तर
- Bohr’s model is applicable only to the hydrogen atom and fails to explain the spectra of multi-electron atoms.
- It cannot explain the fine structure of spectral lines or effects such as the Zeeman and Stark effects.
Notes
Students should refer to the answer according to the question.
संबंधित प्रश्न
Derive the expression for the energy of an electron in the atom.
Answer in one sentence:
Name the element that shows the simplest emission spectrum.
According to Bohr's second postulate, the angular momentum of the electron is the integral multiple of `h/(2pi)`. The S.I unit of Plank constant h is the same as ______
If aO is the Bohr radius and n is the principal quantum number then, state the relation for the radius of nth orbit of the electron in terms of Bohr radius and principal quantum number.
Using de Broglie’s hypothesis, obtain the mathematical form of Bohr’s second postulate.
Calculate the longest wavelength in the Paschen series.
(Given RH =1.097 ×107 m-1)
Calculate the shortest wavelength in the Paschen series if the longest wavelength in the Balmar series is 6563 Ao.
With the increase in principal quantum number, the energy difference between the two successive energy levels ____________.
For a certain atom when the system moves from 2E level to E, a photon of wavelength `lambda` is emitted. The wavelength of photon produced during its transition from `(4"E")/3` level to E is ____________.
If the ionisation potential of helium atom is 24.6 volt, the energy required to ionise it will be ____________.
In the nth orbit, the energy of an electron `"E"_"n"= -13.6/"n"^2"eV"` for hydrogen atom. The energy required to take the electron from first orbit to second orbit will be ____________.
For an electron, discrete energy levels are characterised by ____________.
If m is mass of electron, v its velocity, r the radius of stationary circular orbit around a nucleus with charge Ze, then from Bohr's second postulate, the kinetic energy `"K.E." = 1/2"mv"^2` of the electron in C.G.S. system is 2 equal to ____________.
The time of revolution of an electron around a nucleus of charge Ze in nth Bohr orbit is directly proportional to ____________.
Angular speed of an electron in the ground state of hydrogen atom is 4 × 1016 rad/s. What is its angular speed in 4th orbit?
An electron of mass 'm' is rotating in first Bohr orbit of radius 'r' in hydrogen atom. The orbital acceleration of the electron in first orbit (h = Planck's constant).
In hydrogen atom, during the transition of electron from nth outer orbit to first Bohr orbit, a photon of wavelength `lambda` is emitted. The value of 'n' is [R =Rydberg's constant] ____________.
The de-Broglie wavelength of an electron in 4th orbit is ______.
(r = radius of 1st orbit)
In any Bohr orbit of hydrogen atom, the ratio of K.E to P.E of revolving electron at a distance 'r' from the nucleus is ______.
If Vn and Vp are orbital velocities in nth and pth orbit respectively, then the ratio Vp: Vn is ______.
The third line of the Balmer series, in the emission spectrum of the hydrogen atom, is due to the transition from the ______.
The momentum of an electron revolving in nth orbit is given by ______.
The orbital frequency of an electron in the hydrogen atom ______.
Ultraviolet light of wavelength 300 nm and intensity 1.0 Wm−2 falls on the surface of a photosensitive material. If one percent of the incident photons produce photoelectrons, then the number of photoelectrons emitted from an area of 1.0 cm2 of the surface is nearly ______.
In Bohr’s atomic model, speed and time period of revolution of an electron in n = 3 level are respectively.
The ratio of energies of photons produced due to the transition of an electron of a hydrogen atom from its (i) second to first energy level and (ii) highest energy level to the third level is respectively
