Download Atomic Structure

Atomic Structure
Questions
Level-I:
1. According to J.J. Thompson’s atomic model the mass of an atom is ………
a. Concentrated at the center
b. Negligible and approximately zero
c. Distributed uniformly over the bulk
d. None of the above..
2. According to J.J.Thompson’s atomic model which statement is true?
a. Negative particles are surrounded by the positive bulk.
b. Positive charged particles are surrounded by the negative bulk.
c. Positive and negative charged particles are surrounded by neutral bulk.
d. None of the above.
3. Which of the following scientists developed the "plum-pudding" model of the
atom?
a. John Dalton
b. J.J.Thompson
c. Robert Millikan
d. Henry Moseley
4. In Rutherford's experiment, the foil of which element was used?
a. Gold
b. Silver
c. Aluminum
d. Magnesium
5. In his experiment which particles did Rutherford use to bombard the foil?
a. Alpha-particles
b. Beta-particles
c. Gamma-particles
d. None of the above.
6. Which statement is true according to Rutherford’s experiment?
a. Very small number of α– particles passed through the gold foil without any
deflection.
b. A large number of α– particles bounced back.
c. A very small fraction of the α–particles was deflected by small angles.
d. All the above statements are false.
7. Electrons are _______ ?
a. Positive charged
b. Negative charged
c. Neutrally charged
d. Depends on the atom in which they are present.
8. Charge of an electron is ____ ?
a. -1.6×10-19 C
b. +1.6×10-19 C
c. 0C
d. None of the above.
9. Which of the particles below is neutral in charge?
a. Electron
b. Proton
c. Neutron
d. None of the above.
10. What is the charge of a proton?
a. -1.6×10-19 C
b. +1.6×10-19 C
c. 0C
d. None of the above.
Level-II:
11. What is the reason for Rutherford to infer that an atom contains a lot of
empty space?
a. Since most alpha particles are deflected from the foil.
b. Since most of the alpha particles passed the foil undeflected.
c. Since it was earlier proposed by J.J.Thompson.
d. Since atoms are meant to be empty.
12. What is the difference between J.J.Thompson's and Rutherford’s theories with
respect to the mass of an atom?
a. Thompson model has mass concentrated at the nucleus and Rutherford’s
model has mass distributed over bulk.
b. Thompson model’s atom has no mass and Rutherford’s model has mass
distributed over the bulk.
c. Thompson model and Rutherford’s model has mass distributed over the bulk.
d. Thompson’s model has mass distributed over the bulk and Rutherford’s model
has most of the mass concentrated at the nucleus.
13. Is there a chance for the electrons to come out in a stable state of the atom in
Rutherford’s model and why?
a. Yes because of high speeds.
b. Yes because there is no attractive force holding the electrons.
c. No because the outer most atomic shell does not allow electrons to come out.
d. No because the nucleus and electrons are held together by electrostatic forces.
14. The volume of the nucleus of an atom when compared to the extra nuclear
part is_________.
a. Smaller
b. Bigger
c. Equal
d. Unpredictable
15. The fixed circular paths around the nucleus are called_________.
a. Orbitals
b. Orbits
c. Nucleons
d. Mesons
16. What would have happened to the Rutherford’s experiment if the actual
atomic model is as stated as J.J.Thompson?
a. All alpha-particles would have passed freely with little or no deflection.
b. All the alpha-particles would have been embedded in the atom.
c. All the alpha-particles would have been deflected back.
d. The foil would have been burnt away.
17. In which case can the atomic number and atomic mass be equal for an atom?
a. If protons are zero in the atom.
b. If neutrons are zero in the atom.
c. If electrons are zero in the atom.
d. All the above.
18. Consider two atoms A1 and B1. If the atomic number is more in A1 atom than
in the B1 atom, in which atom is the chance of holding electrons tightly more?
a. A1
b. B1
c. Both
d. Can’t say as the atomic number has no relation with the chance of holding
electrons tight.
19. The nucleus contains __________________.
a. Electrons and protons
b. Protons and neutrons
c. Only protons
d. Only neutrons
20. If all the alpha-particles had deflected from the gold foil in Rutherford’s
experiment, then the inference would have been ______ ?
a. the atom contains entirely negative charge
b. the atom contains entirely positive charge
c. the atom contains no charge
d. the atom contains all neutrons.
Level-III:
21. The ratio of charge and mass would be greater for _____________.
a. Proton
b. Neutron
c. Electron
d. Alpha
22. If the atomic weight of an element is 23 times that of the lightest element and
it has 11 protons, then it contains:
a. 11 protons, 23 neutrons, 11 electrons
b. 11 protons, 12 neutrons, 11 electrons
c. 11 protons, 11 neutrons, 11 electrons
d. 11 protons, 11 neutrons, 23 electrons.
23. According to Neils Bohr, what happens when an electron jumps from one
orbit to another?
a. The electron disappears.
b. The energy is emitted or absorbed by the electron.
c. The electron changes into a neutron.
d. It disappears into the nucleus.
24. According to Planck’s relation which is true (where ‘E2’ and ‘E1’ are energy
level of electron after and before jumping respectively, ‘h’ is Planck’s constant
and ‘v’ is frequency of electromagnetic radiation)?
a. E2-E1 = hv
b. E2-E1 = h
c. E2 - E1 = v
d. E2 - E1 = 0
25. According to Bohr, what is the behavior of an electron when orbiting in its
respective orbit?
a. Radiates energy.
b. Does not radiate or absorb any energy.
c. Absorbs energy.
d. Radiates and absorbs energy.
26. In a neutral atom which is true ?
a. Number of protons = number of electrons
b. Number of protons > number of electrons
c. Number of protons < number of electrons
d. Number of protons = Number of electrons = 0.
27. Which of the following is true with respect to a neutral atom ?
a. Electrons occupy almost the entire mass and the nucleus occupies almost the
entire volume.
b. Electrons occupy almost the entire volume and the nucleus occupies almost the
entire mass.
c. Electrons occupy almost both mass and volume.
d. Nucleus occupies almost both mass and volume.
28. Which of the following have approximately the same mass?
a. Protons and electrons
b. Electrons and neutrons
c. Protons and neutrons
d. Protons, electrons and neutrons.
29. Protons and neutrons are ____________.
a. Approximately 2000 times heavier than electrons
b. Approximately 2000 times lighter than electrons
c. Are the same weight as electrons
d. Approximately 10000 times heavier than electrons
30. If a beam of each of Proton, neutron and electron is passed between two
electrically charged plates - one positive and one negative then what will happen?
a. The proton beam deflects towards positive plate, electron towards positive and
neutron will go straight.
b. The proton beam deflects towards negative plate, electron towards positive
and neutron will go straight.
c. The proton beam deflects towards negative plate, electron towards negative
and neutron will go straight.
d. The proton beam deflects towards positive plate, electron towards negative
and neutron will go straight.
Answers
1. c
2. a
3. b
4. a
5. a
6. c
7. b
8. a
9. c
10. b
11. b
12. d
13. d
14. a
15. b
16. a
17. b
18. a
19. b
20. b
21. c
22. b
23. b
24. a
25. b
26. a
27. b
28. c
29. a
30. b