The positively charged part of the atom possesses most of the mass in ____________. - Physics

Fill in the Blanks

The positively charged part of the atom possesses most of the mass in ____________.


  • Rutherford’s model

  • both the models



The positively charged part of the atom possesses most of the mass in both the models.

  Is there an error in this question or solution?
Chapter 12: Atoms - Exercise [Page 435]


NCERT Physics Class 12
Chapter 12 Atoms
Exercise | Q 12.1 (e) | Page 435
NCERT Physics Class 12
Chapter 12 Atoms
Exercise | Q 1.5 | Page 435


With the help of a neat labelled diagram, describe the Geiger- Marsden experiment

Thorium 90Th232 is disintegrated into lead 82Pb200. Find the number of α and β particles emitted in disintegration.

The size of the atom in Thomson’s model is ____________ the atomic size in Rutherford’s model.

Suppose you are given a chance to repeat the alpha-particle scattering experiment using a thin sheet of solid hydrogen in place of the gold foil. (Hydrogen is a solid at temperatures below 14 K.) What results do you expect?

Answer the following question, which help you understand the difference between Thomson’s model and Rutherford’s model better.

Keeping other factors fixed, it is found experimentally that for small thickness t, the number of α-particles scattered at moderate angles is proportional to t. What clue does this linear dependence on t provide?

Define the distance of closest approach. An α-particle of kinetic energy 'K' is bombarded on a thin gold foil. The distance of the closest approach is 'r'. What will be the distance of closest approach for an α-particle of double the kinetic energy?

Write two important limitations of Rutherford's nuclear model of the atom.

An electron in an atom revolves round the nucleus in an orbit of radius r with frequency v. Write the expression for the magnetic moment of the electron.

In a Geiger-Marsden experiment, calculate the distance of closest approach to the nucleus of Z = 80, when a α-particle of 8Mev energy impinges on it before it comes momentarily to rest and reverses its direction.

How will the distance of closest approach be affected when the kinetic energy of the α-particle is doubles?

The total energy of an electron in the ground state of the hydrogen atom is -13·6 eV. Its total energy, when a hydrogen atom is in the first excited state, is: 

The model that best explains the results of Geiger-Marsden experiment is ______.

The first line of Balmer series (Hα) in the spectrum of hydrogen is obtained when an electron of hydrogen atom goes from ______.

If the radius of second electron orbit in hydrogen atom be r then the radius of the third orbit will be ______.

As compared to 12C atom, 14C atom has ______.

In a capillary tube, water rises by 1.2 mm. The height of water that will rise in another capillary tube having half the radius of the first is:

Which one of the following statements does not hold good when two balls of masses m1 and m2 undergo elastic collision?

The equation of trajectory of a projectile is given by y = `"x"/sqrt3 - "gx"^2/20`, where x and y are in metres. The maximum range of the projectile is:

Plutonium decays with half of 24000 years. If plutonium is store for 72000 yrs. The fraction of .its that remain:-

The radius of electron's second stationary orbit in Bohr's atom is R. The radius of 3rd orbit will be:-

The ratio of the frequencies of the long wave length its of Lyman Balmer series of hydrogen spectrum is

Which of the following transition in a hydrogen atom emit photon of the highest frequency:

An alpha particle has

Nucleolus of an atom of mass No. 24 and charge no. 11 consists of

Assume that there is no repulsive force between the electrons in an atom but the force between positive and negative charges is given by Coulomb’s law as usual. Under such circumstances, calculate the ground state energy of a He-atom.

The energy of hydrogen atom in an orbit is −1.51 eV. What are the kinetic and potential energies of the electron in this orbit?

The energy levels of a certain atom for first, second and third levels are E, 4E/3 and 2E, respectively. A photon of wavelength λ is emitted for a transition 3 `→` 1. What will be the wavelength of emission for transition 2 `→` 1?

According to Bohr model, magnetic field at centre (at the nucleus) of a hydrogen atom due to motion of electron in the ninth orbit is proportional to:

If λa, λb and λc represent the Kα, Kβ and Lα transition wavelengths in a hydrogen atom, respectively. Then which of the following is correct?

The shortest wavelength of the Brackett series of a hydrogen like atom of atomic number Z is same as the shortest wavelength of the Balmer series of hydrogen atom, then the value of Z is ______.

Choose the correct option from the following options given below:

An alpha nucleus of energy `1/2`mv2 bombards a heavy nuclear target of charge Ze. Then the distance of closest approach for the alpha nucleus will be proportional to ______.

  1. v2
  2. `1/"m"`
  3. `1/"v"^2`
  4. `1/"Ze"`

In the Rutherford experiment, α-particles are scattered from a nucleus as shown. Out of the four paths, which path is not possible? 

When alpha particles are sent through a thin gold foil, most of them go straight through the foil, because ______.


      Forgot password?
Use app×