Written Assignment 10: Nuclear ReactionsAnswer all assigned questions and problems and show all work.
1. How do nuclear reactions differ from ordinary chemical reactions? (3 points)
2. What is the difference between radioactive decay and nuclear transmutation? (3 points)
3. The table below is a summary of different modes of nuclear decay. Fill in the changes in
atomic number (Z), number of neutrons (N), and mass number (A) in each case. Use “+”
sign for increase, “– “sign for decrease, and “0” for no change. Provide the symbol for
each elementary particle involved in the decay process. (12 points)
Particle Symbol Change in:
4. Complete the following nuclear equations and identify X in each case. (15 points)
a. 222Rn → 218Po + X
b. 231Th → 231Pa + X
c. 226Ra → 4He + X
d. 14C → 14N + X
e. 20F → –1β + X
5. Which of the reactions in exercise 4 show alpha decay? Which show beta decay?
6. Define half-life. Write the equation relating the half-life of a first-order reaction to the
rate constant. (3 points)
7. If uranium-238 has a half-life of 45 billion years, how many years would it take for a 10gram sample of U-238 to decrease to 2.5 grams? (3 points)
8. The radioactive decay of Tl-206 to Pb-206 has a half-life of 4.20 min. Starting with 5.00
× 1022 atoms of Tl-206, calculate the number of such atoms left after 42.0 min. (10
9. Strontium-90 is one of the products of the fission of uranium-235. This strontium isotope
is radioactive, with a half-life of 28.1 yr. Calculate how long (in yr) it will take for 1.00 g
of the isotope to be reduced to 0.200 g by decay. (10 points)
10. The carbon-14 decay rate of a sample obtained from a young tree is 0.260 disintegration
per second per gram of the sample. Another wood sample prepared from an object
recovered at an archaeological excavation gives a decay rate of 0.186 disintegration per
second per gram of the sample. What is the age of the object? Carbon-14 has a half-life of
5730 years. (10 points)
11. Which of the following poses a greater health hazard: a radioactive isotope with a short
half-life or a radioactive isotope with a long half-life? Assume equal molar amounts and
the same type of radiation and comparable energies per particle emitted. (5 points)
12. Naturally occurring iodine is iodine-127. Medically, radioactive isotopes of iodine-125
and iodine-120 are used.
a. Write the atomic symbols for each isotope. (3 points)
b. In what ways are the isotopes similar? (3 points)
c. In what ways do they differ? (3 points)
13. How does ionizing radiation cause damage to cells of the body? (3 points)
14. Indicate whether each of the following are characteristic of the fission or fusion process
or both. (9 points)
Neutrons bombard a nucleus.
The nuclear process occurring in the sun.
A large nucleus splits into smaller nuclei.
Small nuclei combine to form larger nuclei.
Very high temperatures are required to initiate the reaction.
Large amounts of energy are released when the nuclear reaction occurs.
The nuclear process occurring in nuclear power plants.
The nuclear process occurring in atomic bombs.
Less radioactive waste is produced.
Copyright © 2020 by Thomas Edison State University. All rights reserved.
Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.
You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.Read more
Each paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.Read more
Thanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.Read more
Your email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.Read more
By sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.Read more