A freshly prepared radio-isotope has activity \(64\) times the allowed level. If half-life is \(3\) h, then how long one must wait before using the isotope in radio-diagnosis?
1. \(24\) h
2. \(18\) h
3. \(12\) h
4. \(6\) h
The energy equivalent of \(0.5\) g of a substance is:
1. \(4.5\times10^{13}\) J
2. \(1.5\times10^{13}\) J
3. \(0.5\times10^{13}\) J
4. \(4.5\times10^{16}\) J
When a uranium isotope \(_{92}^{235}\mathrm{U}\) is bombarded with a neutron, it generates \(_{36}^{89}\mathrm{Kr}\) three neutrons and:
1. | \(_{40}^{91}\mathrm{Zr}\) | 2. | \(_{36}^{101}\mathrm{Kr}\) |
3. | \(_{36}^{103}\mathrm{Kr}\) | 4. | \(_{56}^{144}\mathrm{Ba}\) |
The rate of radioactive disintegration at an instant for a radioactive sample of half-life 2.2 . The number of radioactive atoms in that sample at that instant is:
1. 3.7
2. 3.17
3. 3.17
4. 3.17
Two stable isotopes of lithium \(^{6}_{3}\mathrm{Li}\) and \(^{7}_{3}\mathrm{Li}\) have respective abundances of \(7.5\%\) and \(92.5\%\). These isotopes have masses \(6.01512~\text{u}\) and \(7.01600~\text{u}\), respectively. The atomic mass of lithium is:
1. \(6.940934~\text{u}\)
2. \(6.897643~\text{u}\)
3. \(7.863052~\text{u}\)
4. \(7.167077~\text{u}\)
The three stable isotopes of neon: have respective abundances of 90.51%, 0.27%, and 9.22%. The atomic masses of the three isotopes are 19.99 u, 20.99 u, and 21.99 u, respectively. The average atomic mass of neon is:
1. 20.1709 u
2. 21.7037 u
3. 20.1771 u
4. 21.0097 u
What is the binding energy (in MeV) of a nitrogen nucleus ?
1. 102.7 MeV.
2. 100.7 MeV.
3. 104.7 MeV.
4. 108.7 MeV.
A radioactive isotope has a half-life of T years. How long will it take the activity to reduce to 3.125% of its original value?
1. T years.
2. 4T years.
3. 3T years.
4. 5T years.
What is the amount of necessary to provide a radioactive source of 8.0 mCi strength? The half-life of is 5.3 years.
1.
2.
3.
4.
A given coin has a mass of 3.0 g. How much nuclear energy would be required to separate all the neutrons and protons from each other? For simplicity assume that the coin is entirely made of atoms (of mass 62.92960 u).
1. \(2.5296\times10^{12}\) MeV
2. \(1.581\times10^{25}\) MeV
3. \(3.1223\times10^{20}\) MeV
4. \(931.02\times10^{19}\) MeV