363953
Which of the following cannot be emitted by radioactive substances during their decay?
1 Protons
2 \(\gamma \) rays
3 Helium nuclei
4 Electrons
Explanation:
During radioactive decay \(\alpha \) or \(\beta \) or \(\gamma \) particles are emitted. So protons are not emitted.
PHXII13:NUCLEI
363954
A nucleus with \(Z = 92\) emits the following in a sequence: \(\alpha ,{\beta ^ - },{\beta ^ - },\alpha ,\alpha ,\alpha ,\alpha ,\alpha ,{\beta ^ - },\alpha ,\alpha ,{\beta ^ - }.\) The \(Z\) of the resulting nucleus is
363955
Assertion : In a \(\beta^{-}\)decay the daughter nucleus has one proton more than the parent nucleus. Reason : Electron-capture occurs much less frequently than the emission of a positron.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Assertion is true as \(\beta^{-}\)is spontaneous when a nucleus "frees" its neutron which converts to proton and emitting \(\beta^{-}\)as well as \(\bar{\nu}\). \(n \rightarrow p+\left(\beta^{-}\right)+\bar{v}\) Similarly \(\beta^{+}\) process is also spontaneous \(p \rightarrow n+\left(\beta^{+}\right)+v\) But, 'electron-capture' is less frequent. This is a process in which proton-rich nucleus shall capture electron from \(K\) or \(L\) shall (orbiting around nucleus) and then the formation of neutron and \(v\) can take place. But nucleus is very tiny \(\left( { \approx {{10}^{ - 15}}\;m} \right)\) while \(K\)-shell has radius \(0.5\,\mathop {{\rm{ }}A}\limits^{\;\;^\circ } \). So, nuclear weak force may not be always able to capture \(K\)-electron. So correct option is (2).
PHXII13:NUCLEI
363956
Assertion : Electron capture occurs more often than positron emission in heavy elements. Reason : Heavy elements exhibit radioactivity.
1 Both assertion and reason are correct and reason is the correct explanation of assertion.
2 Both assertion and reason are correct but reason is not the correct explanation of assertion.
3 Assertion is correct but reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Electron capture is energitically more favourable than positron emission in heavy nuclei. So option (2) is correct.
363953
Which of the following cannot be emitted by radioactive substances during their decay?
1 Protons
2 \(\gamma \) rays
3 Helium nuclei
4 Electrons
Explanation:
During radioactive decay \(\alpha \) or \(\beta \) or \(\gamma \) particles are emitted. So protons are not emitted.
PHXII13:NUCLEI
363954
A nucleus with \(Z = 92\) emits the following in a sequence: \(\alpha ,{\beta ^ - },{\beta ^ - },\alpha ,\alpha ,\alpha ,\alpha ,\alpha ,{\beta ^ - },\alpha ,\alpha ,{\beta ^ - }.\) The \(Z\) of the resulting nucleus is
363955
Assertion : In a \(\beta^{-}\)decay the daughter nucleus has one proton more than the parent nucleus. Reason : Electron-capture occurs much less frequently than the emission of a positron.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Assertion is true as \(\beta^{-}\)is spontaneous when a nucleus "frees" its neutron which converts to proton and emitting \(\beta^{-}\)as well as \(\bar{\nu}\). \(n \rightarrow p+\left(\beta^{-}\right)+\bar{v}\) Similarly \(\beta^{+}\) process is also spontaneous \(p \rightarrow n+\left(\beta^{+}\right)+v\) But, 'electron-capture' is less frequent. This is a process in which proton-rich nucleus shall capture electron from \(K\) or \(L\) shall (orbiting around nucleus) and then the formation of neutron and \(v\) can take place. But nucleus is very tiny \(\left( { \approx {{10}^{ - 15}}\;m} \right)\) while \(K\)-shell has radius \(0.5\,\mathop {{\rm{ }}A}\limits^{\;\;^\circ } \). So, nuclear weak force may not be always able to capture \(K\)-electron. So correct option is (2).
PHXII13:NUCLEI
363956
Assertion : Electron capture occurs more often than positron emission in heavy elements. Reason : Heavy elements exhibit radioactivity.
1 Both assertion and reason are correct and reason is the correct explanation of assertion.
2 Both assertion and reason are correct but reason is not the correct explanation of assertion.
3 Assertion is correct but reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Electron capture is energitically more favourable than positron emission in heavy nuclei. So option (2) is correct.
363953
Which of the following cannot be emitted by radioactive substances during their decay?
1 Protons
2 \(\gamma \) rays
3 Helium nuclei
4 Electrons
Explanation:
During radioactive decay \(\alpha \) or \(\beta \) or \(\gamma \) particles are emitted. So protons are not emitted.
PHXII13:NUCLEI
363954
A nucleus with \(Z = 92\) emits the following in a sequence: \(\alpha ,{\beta ^ - },{\beta ^ - },\alpha ,\alpha ,\alpha ,\alpha ,\alpha ,{\beta ^ - },\alpha ,\alpha ,{\beta ^ - }.\) The \(Z\) of the resulting nucleus is
363955
Assertion : In a \(\beta^{-}\)decay the daughter nucleus has one proton more than the parent nucleus. Reason : Electron-capture occurs much less frequently than the emission of a positron.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Assertion is true as \(\beta^{-}\)is spontaneous when a nucleus "frees" its neutron which converts to proton and emitting \(\beta^{-}\)as well as \(\bar{\nu}\). \(n \rightarrow p+\left(\beta^{-}\right)+\bar{v}\) Similarly \(\beta^{+}\) process is also spontaneous \(p \rightarrow n+\left(\beta^{+}\right)+v\) But, 'electron-capture' is less frequent. This is a process in which proton-rich nucleus shall capture electron from \(K\) or \(L\) shall (orbiting around nucleus) and then the formation of neutron and \(v\) can take place. But nucleus is very tiny \(\left( { \approx {{10}^{ - 15}}\;m} \right)\) while \(K\)-shell has radius \(0.5\,\mathop {{\rm{ }}A}\limits^{\;\;^\circ } \). So, nuclear weak force may not be always able to capture \(K\)-electron. So correct option is (2).
PHXII13:NUCLEI
363956
Assertion : Electron capture occurs more often than positron emission in heavy elements. Reason : Heavy elements exhibit radioactivity.
1 Both assertion and reason are correct and reason is the correct explanation of assertion.
2 Both assertion and reason are correct but reason is not the correct explanation of assertion.
3 Assertion is correct but reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Electron capture is energitically more favourable than positron emission in heavy nuclei. So option (2) is correct.
363953
Which of the following cannot be emitted by radioactive substances during their decay?
1 Protons
2 \(\gamma \) rays
3 Helium nuclei
4 Electrons
Explanation:
During radioactive decay \(\alpha \) or \(\beta \) or \(\gamma \) particles are emitted. So protons are not emitted.
PHXII13:NUCLEI
363954
A nucleus with \(Z = 92\) emits the following in a sequence: \(\alpha ,{\beta ^ - },{\beta ^ - },\alpha ,\alpha ,\alpha ,\alpha ,\alpha ,{\beta ^ - },\alpha ,\alpha ,{\beta ^ - }.\) The \(Z\) of the resulting nucleus is
363955
Assertion : In a \(\beta^{-}\)decay the daughter nucleus has one proton more than the parent nucleus. Reason : Electron-capture occurs much less frequently than the emission of a positron.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Assertion is true as \(\beta^{-}\)is spontaneous when a nucleus "frees" its neutron which converts to proton and emitting \(\beta^{-}\)as well as \(\bar{\nu}\). \(n \rightarrow p+\left(\beta^{-}\right)+\bar{v}\) Similarly \(\beta^{+}\) process is also spontaneous \(p \rightarrow n+\left(\beta^{+}\right)+v\) But, 'electron-capture' is less frequent. This is a process in which proton-rich nucleus shall capture electron from \(K\) or \(L\) shall (orbiting around nucleus) and then the formation of neutron and \(v\) can take place. But nucleus is very tiny \(\left( { \approx {{10}^{ - 15}}\;m} \right)\) while \(K\)-shell has radius \(0.5\,\mathop {{\rm{ }}A}\limits^{\;\;^\circ } \). So, nuclear weak force may not be always able to capture \(K\)-electron. So correct option is (2).
PHXII13:NUCLEI
363956
Assertion : Electron capture occurs more often than positron emission in heavy elements. Reason : Heavy elements exhibit radioactivity.
1 Both assertion and reason are correct and reason is the correct explanation of assertion.
2 Both assertion and reason are correct but reason is not the correct explanation of assertion.
3 Assertion is correct but reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Electron capture is energitically more favourable than positron emission in heavy nuclei. So option (2) is correct.
