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प्रश्न
State three postulates of Bohr's theory of hydrogen atom.
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उत्तर
Neil Bohr's major three postulates about Bohr's model of the hydrogen atom are:
- Atoms contain a number of stable orbits in which electrons can live without producing energy; each orbit corresponds to a specific amount of energy.
- When an electron jumps from one orbit to another, there is an energy difference equal to E = nhν because the energy of the outer orbit is greater than the energy of the inner orbit.
- The angular momentum of the electron is quantized which can be shown as:
L = `(nh)/(2pi)`, where n = 1, 2, 3, ..........
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संबंधित प्रश्न
Using Bohr’s postulates, derive the expression for the frequency of radiation emitted when electron in hydrogen atom undergoes transition from higher energy state (quantum number ni) to the lower state, (nf).
When electron in hydrogen atom jumps from energy state ni = 4 to nf = 3, 2, 1, identify the spectral series to which the emission lines belong.
The difference in the frequencies of series limit of Lyman series and Balmer series is equal to the frequency of the first line of the Lyman series. Explain.
The numerical value of ionization energy in eV equals the ionization potential in volts. Does the equality hold if these quantities are measured in some other units?
A filter transmits only the radiation of wavelength greater than 440 nm. Radiation from a hydrogen-discharge tube goes through such a filter and is incident on a metal of work function 2.0 eV. Find the stopping potential which can stop the photoelectrons.
The earth revolves round the sun due to gravitational attraction. Suppose that the sun and the earth are point particles with their existing masses and that Bohr's quantization rule for angular momentum is valid in the case of gravitation. (a) Calculate the minimum radius the earth can have for its orbit. (b) What is the value of the principal quantum number n for the present radius? Mass of the earth = 6.0 × 10−24 kg. Mass of the sun = 2.0 × 1030 kg, earth-sun distance = 1.5 × 1011 m.
If the radius of first electron orbit in hydrogen atom be r then the radius of the fourth orbit ill be ______.
The simple Bohr model cannot be directly applied to calculate the energy levels of an atom with many electrons. This is because ______.
An ionised H-molecule consists of an electron and two protons. The protons are separated by a small distance of the order of angstrom. In the ground state ______.
- the electron would not move in circular orbits.
- the energy would be (2)4 times that of a H-atom.
- the electrons, orbit would go around the protons.
- the molecule will soon decay in a proton and a H-atom.
Use Bohr's postulate to prove that the radius of nth orbit in a hydrogen atom is proportional to n2.
The figure below is the Energy level diagram for the Hydrogen atom. Study the transitions shown and answer the following question:
- State the type of spectrum obtained.
- Name the series of spectrum obtained.
