English
Karnataka Board PUCPUC Science 2nd PUC Class 12

The Bohr model for the spectra of a H-atom ______. will not be applicable to hydrogen in the molecular from. will not be applicable as it is for a He-atom. is valid only at room temperature.

Advertisements
Advertisements

Question

The Bohr model for the spectra of a H-atom ______.

  1. will not be applicable to hydrogen in the molecular from.
  2. will not be applicable as it is for a He-atom.
  3. is valid only at room temperature.
  4. predicts continuous as well as discrete spectral lines.

Options

  • a and b

  • c and d

  • b and c

  • a and d

MCQ
Fill in the Blanks
Advertisements

Solution

a and b

Explanation:

Bohr proposed a model for the hydrogen atom which is also applicable for some lighter atoms in which a single electron revolves around a stationary nucleus of positive charge Ze (called a hydrogen-like atom, e.g.: H, He+, Li+2, Na+1 etc). It is not applicable to hydrogen in the molecular form and also, it will not be applicable as it is for a He-atom.

shaalaa.com
  Is there an error in this question or solution?
Chapter 12: Atoms - Exercises [Page 77]

APPEARS IN

NCERT Exemplar Physics Exemplar [English] Class 12
Chapter 12 Atoms
Exercises | Q 12.10 | Page 77

RELATED QUESTIONS

What is the maximum number of emission lines when the excited electron of an H atom in n = 6 drops to the ground state?


Show that the circumference of the Bohr orbit for the hydrogen atom is an integral multiple of the de Broglie wavelength associated with the electron revolving around the orbit.


If the velocity of the electron in Bohr’s first orbit is 2.19 × 106 ms-1, calculate the de Broglie wavelength associated with it.


if `E_p` and `E_k` represent potential energy and kinetic energy respectively, of an orbital electron, then, according to B9hr's theory:

a)`E_k = -E_p"/"2`

b) `E_k = -E_p`

c) `E_k = -2E_p`

d) `E_k = 2E_p`

 


On the basis of Bohr's theory, derive an expression for the radius of the nth orbit of an electron of the hydrogen atom.


Using Bohr’s postulates for hydrogen atom, show that the total energy (E) of the electron in the stationary states tan be expressed as the sum of kinetic energy (K) and potential energy (U), where K = −2U. Hence deduce the expression for the total energy in the nth energy level of hydrogen atom.


Find the wavelength of the radiation emitted by hydrogen in the transitions (a) n = 3 to n= 2, (b) n = 5 to n = 4 and (c) n = 10 to n = 9.


A neutron having kinetic energy 12.5 eV collides with a hydrogen atom at rest. Nelgect the difference in mass between the neutron and the hydrogen atom and assume that the neutron does not leave its line of motion. Find the possible kinetic energies of the neutron after the event.


Obtain Bohr’s quantisation condition for angular momentum of electron orbiting in nth orbit in hydrogen  atom on the basis of the wave picture of an electron using de Broglie hypothesis. 


According to Bohr, 'Angular momentum of an orbiting electron is quantized'. What is meant by this statement?


If l3 and l2 represent angular momenta of an orbiting electron in III and II Bohr orbits respectively, then l3: l2 is :


Write postulates of Bohr’s Theory of hydrogen atom.


What is the energy in joules released when an electron moves from n = 2 to n = 1 level in a hydrogen atom?


According to Bohr’s theory, the angular momentum of an electron in 5th orbit is ______.


If the radius of first electron orbit in hydrogen atom be r then the radius of the fourth orbit ill be ______.


According to the Bohr theory of H-atom, the speed of the electron, its energy and the radius of its orbit varies with the principal quantum number n, respectively, as:


The angular momentum of electron in nth orbit is given by


A set of atoms in an excited state decays ______.


The inverse square law in electrostatics is |F| = `e^2/((4πε_0).r^2)` for the force between an electron and a proton. The `(1/r)` dependence of |F| can be understood in quantum theory as being due to the fact that the ‘particle’ of light (photon) is massless. If photons had a mass mp, force would be modified to |F| = `e^2/((4πε_0)r^2) [1/r^2 + λ/r]`, exp (– λr) where λ = mpc/h and h = `h/(2π)`. Estimate the change in the ground state energy of a H-atom if mp were 10-6 times the mass of an electron.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×