Multiple Choice QuestionsAzimuthal quantum number defines :
e/m ratio of electron
angular momentum of electron
spin of electron
magnetic momentum of electron
Assertion : Nuclear binding energy per nucleon is in the order -
Reason : Binding energy per nucleon increases linearly with difference in number of neutrons and protons.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
D.
If both assertion and reason are false.
Binding energy per nucleon of 3Li7 (5.38 MeV) is lesser than 2He4 (7.08 MeV) as helium is found to be more stable than Li. As the atomic mass number increases, the binding energy per nucleon decreases. As the atomic number and the atomic mass number increase, the repulsive electrostatic forces within the nucleus increase due to the greater number of protons in the heavy elements. To overcome this increased repulsion, the proportion of neutrons in the nucleus must increase to maintain stability. This increase in the neutron-to-proton ratio only partially compensates for the growing proton-proton repulsive force in the heavier, naturally occurring elements. Because the repulsive forces arc increasing, less energy must be supplied, on the average, to remove a nucleon from the nucleus. The binding energy per nucleon has decreased. The binding energy per nucleon of a nucleus is an indication of its degree of stability. Generally, the more stable nuclides have higher binding energy per nucleon than the less stable ones. The increase in binding energy per nucleon as the atomic mass number decreases from 260 to 60 is the primary reason for the energy liberation in the fission process. The increase in the binding energy per nucleon as the atomic mass number increases from 1 to 60 is the reason for the energy liberation in the fusion process, which is the opposite reaction of fission.
The quantum number m of a free gaseous atom is associated with
the effective volume of the orbital
the shape of the orbital
the spatial orientation of the orbital
the energy of the orbital in the absence of a magnetic field.
Assertion : emits a positron giving .
Reason : In β+ emission neutron is transformed into proton.
If both assertion and reason are true and the reason is the correct explanation of the assertion.
If both assertion and reason are true and the reason is not the correct explanation of the assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Which of the following arrangements is possible?
| n | l | m | s |
| 5 | 2 | 2 |
| n | l | m | s |
| 2 | 2 | 0 |
| n | l | m | s |
| 3 | -2 | 1 |
| n | l | m | s |
| 0 | 0 | 1 |
Which of the following is the correct sequence of atomic weights of the given elements?
Ni> Co> Fe
Fe> Co> Ni
Co> Fe> Ni
Co> Ni> Fe
Assertion : Hydrogen nuclei combines to form helium nuclei then energy is released.
Reason: Binding energy/nucleon of He is greater than hydrogen.
If both Assertion and Reason are true and Reason is the correct explanation of Assertion
If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
If Assertion is true but Reason is false.
If Assertion is false but Reason is true.
Assertion : Water is used as a moderator in nuclear reactor.
Reason : Moderator is a light substance that absorb neutrons.
If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
If Assertion is true but Reason is false.
If Assertion is false but Reason is true.
Assertion : Ionisation potential of B (atomic no.5) is less than Be (atomic no. 4).
Reason : The first electron released from Be is of p-orbital but that from B is of s-orbital.
If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
If Assertion is true but Reason is false.
If Assertion is false but Reason is true.
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