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1. For each pair of isotopes listed, predict which one is more stable:

A) 9Li B) 6Li C) 11Li D) All of them are stable

3 3 3

2. Which one is more stable:

A) 17Ne C) 21Ne C) 20Ne D) 23Ne

10 10 10 10

3. Calculate the nuclear binding energy (in J) and the binding energy per nuclear of the following isotopes: 184W (183.9510 amu).

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A) 4.55 x 10-12 J; 1.14 x 10-12 J/nucleon

B) 5.60 x 10-12 J; 1,14 x 10-12 J/nucleon

C) 4.55 x 10-12 J; 2.14 x 10-12 J/nucleon

D) 5.60 x 10-12 J; 2.14 x 10-12 J/nucleon

4. In the thorium decay series, thorium-232 loses a total of 6 alpha particles and 4beta particles in a 10-stage process. What is the final isotope produced?

A) 201Hg B) 204Ti C) 209Bi D) 208Pb

80 81 83 82

5. Polonium-208 is an alpha emitter with a half-life of 3 years. How many milligrams of polonium from an original sample of 4.00mg will remain after 12 years?

A) 0.420 mg B) 0.250 mg C) 0.345 mg D) 0.302 mg

6. The half-life of 90Sr is 25 years. What fraction of the atoms in a sample of 90Sr would remain 100 years later?

A) 0.0313 B) 0.125 C) 0.0625 D) 0.25

7. The fastest moving form of radiation is ______ radiation.

A) gamma B) beta C) alpha D) positron

8. The lowest speed ejected from a nucleus during radioactive decay is a (an):

A) beta particle B) gamma ray C) alpha particle D) None of the above

9. CFCs absorb UV radiation in the stratosphere producing ________ atoms

A) carbon B) fluorine C) UV radiation D) chlorine

10. Calculate the wavelength (in nm) of a photon needed to dissociate an O3 molecule:

O3 ------- O + O2 DH = 107.2 KJ/mol

A) 2 31 x 103 nm B) 1.12 x 103 nm C) 4.23 x 103 nm D) 3.12 x 103 nm

11. Why are CFCs not decomposed by UV radiation in the troposphere?

A) the wavelength is not long enough

B) CFCs cannot decompose under any situation

C) the wavelength is not short enough

D) none of the above