A radioactive source emits 2.4-MeV neutrons at the rate of 7773 neutrons per second. The number of atoms in the source is 2.38x10^9. What is the activity of the source, in nano-curies (nCi)?
A radioactive source emits 2.4-MeV neutrons at the rate of 7773 neutrons per second. The number...
Americium-241 is a radioactive isotope that emits alpha particles. The rate constant for this radioactive decay is 1.47 x 10-3 per year. a. What is the half-life for the decay of americium-241? b. How long will it take for 45.0% of the americium to decay?
please show all formulas/work 5. The decay constant of a radioactive source is 0.300/minute. - How much time must elapse before the activity is reduced to… (a) 85%? (b) 25%? (c) 5%? B) The half-life of a radioactive source is 14.0 minutes. - How much time must elapse before the activity is reduced by… (a) 70%? (b) 45%? (c) 20%? C) Radon-222 has a physical half-life of 30.0 days. A 10.24 microgram piece of this source is placed in storage....
Assuming an average energy of 210 MeV per fission, calculate the number of fissions per second needed for a 500 MW reactor.
(d) Due to alpha decay, l mole of uranium-238 produces 2.96 106 alpha particles per second. Find the half-life, giving your answer in units of years. [5 marks] (e) The average mass of the atoms in a 0.100 kg block of pure carbon is 12.01 u. A small fraction of the atoms are radioactive, with a decay constant of 3.90 x 10-12s. If the activity of the carbon block is 97.8 Bq, calculate what fraction of the atoms are radioactive...
The following questions pertain to radioactive decay, which are first-order reactions. • Decay constant = rate constant • Activity is the number of nuclei (N) decaying per unit time 1. a. What is the decay constant for the B emission of 3H given ty = 12.26 yr? b. What fraction of tritium atoms in a sample remains after 100.0 yr? c. If the original number of tritium atoms was 1.50 x 1018, what is the number remaining? and that a....
A 60Co source with activity 2.5×10−4 Ci is imbedded in a tumor that has mass 0.480 kg . The source emits γ photons with average energy 1.25 MeV. Half the photons are absorbed in the tumor, and half escape. a) What energy is delivered to the tumor per second? E = 9.3×10−7 J/s b) What absorbed dose (in rad) is delivered per second? D= 1.9×10−4 rad c) What equivalent dose (in rem) is delivered per second if the RBE for these...
Part 3 7. A detector counts the number of particles emitted from a radioactive source over the course of 10-second intervals. For 180 such 10-second intervals, the following counts were observed: Count # intervals 34 3 13 This table states, for example, that in 34 of the 10-second intervals a count of 2 was recorded. Sometimes, however, the detector did not function properly and recorded counts over intervals of length 20 seconds. This happened 20 times and the recorded counts...
Alpha particles of kinetic energy 6.4 MeV are incident at a rate of 3.2 107 per second on a gold foil of thickness 3.2 10-6 m. A circular detector of diameter 1.0 cm is placed 13 cm from the foil at an angle of 30° with the direction of the incident alpha particles. At what rate does the detector measure scattered alpha particles? (The molar mass of gold is 197.0 g/mol and its density is 19.3 g/cm3.) Alpha particles of...
Problem 3: Intensity from a distant light source (25 points) Consider an isotropic light source that emits EM radiation with wavelength A and power Po. (Isotropic- uniformly in all directions). In addition, consider a detector with area a, facing the source which is a long distance R away. (a) Derive a formula for the amplitude of the electric field at the detector (b) Derive a formula for the number of photons per unit time that strike the detector. What is...
the Arrhenius Equation for the rate constant ka zpe is the number of collisions per second, and p is the orientation factor For the reaction A B , z = 1012 collision per second, and p = 0.5. At a temperature T 300.0 K, how many effective collisions occur per second CASO SO,000 17. The rate constant (ka) of a reaction is 3.46 X 102/sec at 298 K. What is the rate constant (kz) at 350.0 K, if the activation...