CHEM Week 6 Assignment

Week 6 Assignment: (20 points)

1. In your own words, describe what is occurring during the process of electron beta decay, explaining what is ejected from the unstable nucleus and focusing subatomic changes. (2 points for clear and accurate description).

2. Write balanced chemical reactions for the following: (1 point each, 4 points total)

1. Cobolt-60 undergoes beta decay

1. Americium-241 undergoes alpha decay

1. Copper-60 undergoes positron emission

1. Gallium-66 undergoes electron capture

3. Strontium-89 is an isotope used in the treatment of bone cancer and has a half-life of 50.57 days. If 20 grams of this isotope is injected into a patient, how much will remain after 354 days? (1 point for correct answer with all work shown).

4. An isotope has a half life of 45 minutes. What % of a sample of this isotope will remain after 1.5 hours, assuming that we start with 100%?  (1 point for correct answer with all work shown).

5. Compare and contrast a source of ionizing energy with a source of non-ionizing energy. (1 point)

MC/select all questions: 1 point each

6. Which of the following would be an exothermic process?  There may be more than one correct answer
7. A) Magma solidifying
8. B) Tinder burning
9. C) Ice cream melting
10. D) Ice melting
11. Which polymer(s) is/are found in the human body? (select all that apply).
12. A) Polypropylene
13. B) DNA
14. C) Protein
15. D) Cellulose

8. Which of the following directly illustrates the 1^st law of thermodynamics:
9. A) Heat flows from a hot stone to the cool ground spontaneously.
10. B) The energy from the sun
11. C) Ice melts when heated
12. D) In a small/insulated chamber, a piece of wood burns burns; however, the total energy within the system is unchanged.

9. Molybdenum-99 decays by beta decay emission, resulting in an electron and:
10. A) Technetium-43
11. B) Technetium-99
12. C) Niobium-42
13. D) Niobium-99

10. In the process of electron capture:
11. A) an electron and a proton react to form a neutron
12. B) an electron and a neutron react to form to a proton
13. C) a proton is converted to a neutron and an electron.
14. D) a neutron is converted to a proton and an electron.

11. In alpha decay, what change is observed in the atomic number?
12. A) decrease of 2
13. B) decrease of 4
14. C) increase of 2
15. D) no change

12. In beta decay, what change is observed in the atomic number?
13. A) decrease of 2
14. B) no change
15. C) increase of 1
16. D) decrease of 1

13. An isotope with 82 neutrons and 49 protons undergoes positron emission. How many neutrons will be in the new isotope?
14. A) 81
15. B) 82
16. C) 83
17. D) 48

14. Which of the following is an exothermic process”
15. A) photosynthesis
16. B) ethanol evaporating
17. C) Water Freezing
18. D) octane evaporating

15. You have four potential imaging isotopes, A, B, C, and D. Their half-lives are 50 seconds, 10 mins, 18 hours, and 6 years respectively. Which of these would you choose for medical imaging applications?
16. A) A
17. B) B
18. C) C
19. D) D

16. This radioactive decay process causes a decrease in the atomic number. More than one answer may be correct:
17. A) Alpha
18. B) Beta
19. C) Gamma
20. D) Positron Emission