Concepts Of Physics MCQ Edition [Volume 2]
- Exam
- Concepts Of Physics MCQ Edition [Volume 2]
- Subject
- Physics
- Chapter
- The Nucleus
Concepts Of Physics MCQ Edition [Volume 2] · Physics · The Nucleus
Determine the maximum energy that a positron can possess during the...
Determine the maximum energy that a positron can possess during the -decay of ^{11}\text{C}. The atomic masses of ^{11}\text{C} are and , respectively.
Options
- A
- B
- C
- D
Correct answer
C.
Step-by-step solution
The decay equation is given by:
^{11}_{6}\text{C} \rightarrow ^{11}_{5}\text{B} + e^{+} + \nu_{e}Q = [m_{N}(^{11}\text{C}) - m_{N}(^{11}\text{B}) - m_e]c^2m_{N}(^{11}\text{C}) = m(^{11}\text{C}) - 6m_em_{N}(^{11}\text{B}) = m(^{11}\text{B}) - 5m_eQ = [m(^{11}\text{C}) - 6m_e - (m(^{11}\text{B}) - 5m_e) - m_e]c^2Q = [m(^{11}\text{C}) - m(^{11}\text{B}) - 2m_e]c^2m(^{11}\text{C}) = 11.0114 \text{ u}m(^{11}\text{B}) = 11.0093 \text{ u}m_e = 0.0005486 \text{ u}\Delta m = 11.0114 - 11.0093 - 2(0.0005486)\Delta m = 0.0021 - 0.0010972 = 0.0010028 \text{ u}1 \text{ u} = 931 \text{ MeV}/c^2Q = 0.0010028 \times 931 \text{ MeV}Q = 0.9336 \text{ MeV} = 933.6 \text{ keV}933.6 \text{ keV}933.6 \text{ keV}
^{11}_{6}\text{C} \rightarrow ^{11}_{5}\text{B} + e^{+} + \nu_{e}Q = [m_{N}(^{11}\text{C}) - m_{N}(^{11}\text{B}) - m_e]c^2m_{N}(^{11}\text{C}) = m(^{11}\text{C}) - 6m_em_{N}(^{11}\text{B}) = m(^{11}\text{B}) - 5m_eQ = [m(^{11}\text{C}) - 6m_e - (m(^{11}\text{B}) - 5m_e) - m_e]c^2Q = [m(^{11}\text{C}) - m(^{11}\text{B}) - 2m_e]c^2m(^{11}\text{C}) = 11.0114 \text{ u}m(^{11}\text{B}) = 11.0093 \text{ u}m_e = 0.0005486 \text{ u}\Delta m = 11.0114 - 11.0093 - 2(0.0005486)\Delta m = 0.0021 - 0.0010972 = 0.0010028 \text{ u}1 \text{ u} = 931 \text{ MeV}/c^2Q = 0.0010028 \times 931 \text{ MeV}Q = 0.9336 \text{ MeV} = 933.6 \text{ keV}933.6 \text{ keV}933.6 \text{ keV}