CBSE Questions for Class 9 Chemistry Structure Of The Atom Quiz 10 - MCQExams.com

The plum pudding model proposed that ____________ are embedded in a charged sphere.
  • nucleus
  • electrons
  • protons
  • all of the above
Which of the following particle has mass closest to the mass of a proton?
  • Neutron
  • Hydrogen molecule
  • Alpha particle
  • Positron
  • Electron
Which of the following was not a conclusion of Rutherford's gold foil experiment?
  • The atom is mainly empty space.
  • The nucleus has a negative charge.
  • The atom has a dense nucleus.
  • Alpha particles can pass through a thin sheet of gold foil.
  • All of the above are correct regarding the gold foil experiment.
 Thomson's atomic model suggested that the atom is:
  • not divisible
  • divisible
  • electrons revolve around nucleus
  • both A and C
Statement 1: A large number of alpha particles were deflected in the Rutherford experiment.
Statement 2: Alpha particles that came close to the nucleus were deflected.

  • Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1.

  • Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation of Statement 1.

  • Statement 1 is correct but Statement 2 is not correct.

  • Statement 1 is not correct but Statement 2 is correct.

  • Both the Statement 1 and Statement 2 is not correct.

The particles which cannot be deflected under the presence of electric field :
  • Electron
  • Proton
  • Neutron
  • None of the above
Statement 1: Neutrons and protons are classified as nucleons.
Statement 2: Neutrons and protons are both located in the energy levels of the atom.

  • Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1.

  • Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation of Statement 1.

  • Statement 1 is correct but Statement 2 is not correct.

  • Statement 1 is not correct but Statement 2 is correct.

  • Both the Statement 1 and Statement 2 are not correct.

Which of the following is not a conclusion of Rutherford experiment?
  • An atom has a very small compact nucleus
  • An atom is mainly empty space
  • An atom's mass is concentrated in the nucleus
  • An atom has a very dense nucleus
  • An atom has a negatively charged nucleus
Which property of atom was explained in Thomson's model?
  • Charge 
  • Nuetrons
  • Stability
  • Nuetrality
Which of the following represents Thomson's atomic model?
  • None of the above
Rutherford's theory assumed which of the following paths for the electron?
  • Elliptical
  • Circular
  • Spiral
  • All the above
Statement I: Rutherford in his experiment observed that, most of the alpha particles passed straight through a thin sheet of gold foil.
Statement II: Most of the space inside the atom is empty.
  • Both statements I and II are true.
  • Statement I is true and statement II is false.
  • Statement I is false and statement II is true.
  • Both statement I and II are false.
  • Ambiguous
Most of the $$\alpha$$-particles passed straight through the gold foil. This proved the existence of ________ in an atom.
  • electrons
  • nucleus
  • empty space
  • positive charge
Who postulated that electrons revolve in orbits around the nucleus?
  • Bohr model
  • deBroglie's wave hypothesis
  • Heisenberg's uncertainty principle
  • Dalton
  • Rutherford
According to J.J Thomson's atomic model, negative charges are embedded in:
  • A lump of positive charge
  • A lump of neutral particles
  • A lump of small atoms
  • The nucleus
Rutherford's experiment on scattering of $$\alpha$$-particles showed for the first time that the atom has
  • Nucleus
  • Electron
  • Proton
  • Neutron
According to Rutherford's atomic model, the entire mass of the atom is concentrated at the ___________.
  • electron
  • nucleus
  • proton
  • none of these
Which of the following observations of $$\alpha$$-ray scattering experiment lead to the presence of small positively charged nucleus in the centre?
  • Most of the $$\alpha$$-particles passed straight
  • Most of the $$\alpha$$-particles rebounded after hitting the atoms
  • Only a few $$\alpha$$-particles deflected away from their path
  • Very few $$\alpha$$-particles rebounded
Multiple Answer Question 
In Bohr's model of the atom:
  • electrons revolve around the nucleus in circular orbits
  • these circular orbits or shells are stationary
  • each shell in associated with a definite amount of energy
  • all shells have equal energy level
What does Bohr's atomic theory explain?
  • About quantum numbers
  • About the shape of sub-levels
  • About nucleus
  • About stationary states
When alpha particles are sent through a thin metal foil, most of them go straight through the foil because:
  • alpha particles are much heavier than electrons.
  • alpha particles are positively charged.
  • most part of the atom is empty.
  • alpha particles move with the high velocity.
The existence of the nucleus was discovered by :
  • J. J. Thomson
  • Rutherford
  • Bohr
  • Goldstein
Rutherford's experiment for the first time proved that an atom has:
  • protons
  • a nucleus
  • neutrons
  • electrons
The total number of electrons in a nitrogen atom and a chlorine atom are $$7$$ and $$17$$ respectively. Find the number of valence electrons in them.
  • $$3, 1$$
  • $$5, 8$$
  • $$4, 1$$
  • $$5, 7$$
Multiple Answer Question.
From Bohr's model radius of the orbit and energy of the hydrogen atom are calculated as :
  • Radius of the 1st orbit is $$0.529 ^oA$$
  • Energy of the 1st orbit is $$-13.6 \ eV$$
  • Energy of the 1st orbit is $$-21.72 \times 10^{-19}J$$
  • Radius of the 1st orbit is $$1.06 ^oA$$
Which of the following conclusions cannot be drawn on Rutherford's atomic model?
  • The total mass of an atom is concentrated at the centre of the atom
  • Nucleus is located inside the atom containing positively charged particles
  • Most of the atom is empty in space
  • Electrons revolve around the nucleus in stationary, circular orbits
Which one of the following about atomic structure is FALSE?
  • The electrons occupy a very large volume compared to the nucleus.
  • The number of protons and electrons in a neutral atom is the same.
  • The number of electrons in an atom can be found by subtracting the atomic number of an element from the mass number of an element.
  • Almost all of the mass of an atom is found in the nucleus.
$$I$$. During Rutherford's gold foil experiment, a beam of alpha particles was directed at a thin sheet of gold foil. This helped to prove the existence of a nucleus in the atom.

$$II$$. Most of the positively charged alpha particles were able to pass undeflected through the gold foil.
  • Statement $$I$$ is true, Statement $$II$$ is true
  • Statement $$I$$ is true, Statement $$II$$ is false
  • Statement $$I$$ is false, Statement $$II$$ is true
  • Statement $$I$$ is false, Statement $$II$$ is false
Which experiment helped to prove the existence of the atomic nucleus?
  • Gold foil
  • Cathod ray tube
  • Emission spectra of hydrogen
  • Oil drop
A beam of alpha-particles is fired at a piece of gold foil as shown in the image. After striking the gold foil in which direction do most of the alpha-particles travel?
517390_d0e67460910d4e2b8ea0e98e55850cab.png
  • $$P$$
  • $$Q$$
  • $$R$$
  • $$S$$
0:0:1


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