Nuclear Chemistry Review

1. Nuclear ChemistryReview

2. An unstable nucleus ____. a. increases its nuclear mass by fission b. increases its half-life c. emits energy when it decays d. expels all of its protons

3. Ionizing radiation that consists of helium nuclei is ____. a. Alpha Radiation b. Beta Radiation c. Gamma Radiation d. Neutron Radiation

4. Which type of ionizing radiation can be blocked by clothing? a. Alpha Radiation b. Beta Radiation c. Gamma Radiation d. Neutron Radiation

5. If an isotope decays by the process of beta emission, ____. a. the mass number changes b. the atomic number changes c. protons are given off d. Both a & b

6. What particle does argon-39 emit when it decays to potassium-39? a. neutron b. electron c. proton d. alpha particle

7. Lead-204 To what element does polonium-208 decay when it emits an alpha particle? • Lead-204 • Lead-207 • Radon-212 • Radon-222

8. Controlled nuclear chain reactions ____. a. take place in nuclear reactors b. are always fusion reactions c. never produce radioactive by-products d. are characteristic of atomic bombs

9. Nuclear fusion ____. a. takes place in the sun b. occurs at low temperatures c. can be controlled in the laboratory d. does not exist

10. A reaction that results in the combining of smaller atomic nuclei is called _______. • Fission • Fusion • Bombardment by beta particles • A chemical reaction

11. What does increasing neutron absorption accomplish in a nuclear reactor? • It speeds up the reaction • It can make the reactor explode • It slows down the reaction. • Trick question, electrons are used in nuclear reactors, not neutrons.

12. Complete the following nuclear reaction: • 231, 88 • 239, 94 • 238, 91 • 235, 90

13. If the half-life of a radioactive material is 8 years, how many years will it take for one half of the original amount of material to decay? • 4 years • 8 years • 16 years • Need more information

14. After 42 days, 2 g of phosphorus-32 has decayed to 0.25 g. What is the half-life of phosphorus-32? • 14 days • 21 days • 32 days • 10.5 days

15. The radioisotope radon-222 has a half-life of 3.8 days. How much of a 73.9g sample of radon-22 would be left after 22.8 days? • 1.1 g • 3.8 g • 18 g • 2.3 g

16. If the half-life of sodium-24 is 15 hours, how much remains from a 10.0-g sample after 60.0 hours? • 160 g • 7.5 g • 1.5 g • 0.63 g

17. The concentration of carbon-14 in a piece of wood from an ancient burial mound indicates that two half-lives of this radioisotope have passed. If the half-life for carbon-14 is 5730 years, approximately how many years ago did this sample of wood die? • 14,000 years • 11,460 years • 5,730 years • Need more information

18. A sample of sodium-25 has a rate constant of 2.94 yrs-1, how long would it take for a sample to decay from 3.00 g to 2.00 g? • 0.225 years • 0.225 hours • 0.138 years • 0.138 hours

19. Sulfur-34 has a half life of 13.9 hours. If a 15 g sample is left in a beaker for 24 hours, how much sulfur will remain? a. 7.5 g • 4.5 g • 5.6 g • 3.8 g

20. How many neutrons are in an alpha particle? • 1 • 2 • 3 • 4

21. What is the approximate ratio of neutrons to protons for stable atoms below atomic number 20? • 1 • 2 • 3 • 4

22. What other particle(s) is involved when Radon-222 produces Polonium-218 and is it through bombardment or decay? • 2 neutrons; decay • 2 neutrons; bombardment • Alpha; decay • Alpha; bombardment