Renewable energy sources course 1. So far, we have learned that the half-life of
ID: 488713 • Letter: R
Question
Renewable energy sources course 1. So far, we have learned that the half-life of a thermal neutron is approximately 10.3 minutes. On the other hand, the most probable energy of a thermal neutron is around 0.025 eV at room temperature. In what distance will half of a beam of 0.025 eV neutrons have decayed? (4) 2. Some experiments concluded that the radionuclide U922 decays into a lead isotope 38 through the successive emissions of eight alpha particles and six electrons. a. Through simple calculations, can you determine what the lead isotope will be produced by this method (2) b. Write down a balance nuclear equation for this process. (1) c. Perform energy balance to determine the total energy released during this transmutation process. (3)Explanation / Answer
1) Given- The most probable energy of a thermal neutron is 0.025 eV
The half-life of the neutron is 10.3 min = 10.3 x 60 s
Half of the neutrons in the beam will have decayed, so calculate how far 0.025 eV neutrons travel in this time.
Convert eV to Joules -
0.025 eV x 1.6 x 10^-19 neutron energy in Joules
= 4.0 x 10^-21 J
Mass of neutron = 1.675 x 10^-27 Kg
V =
V = 2 x( 4.0 x 10^-20 J)/(1.675 x 10^-27)^1/2
v = 2.185 x 10^3 meters/second
Distance = speed x time
2.185 x10^3m/s x (10.3 x 60)s
Distance = 1.35 x 10^6 meters