Chapter 20

What are the advantages of a fusion reactor over a fission reactor? What are the practical difficulties in operating a large-scale fusion reactor?

Describe how you would use a radioactive iodine isotope to demonstrate that the following process is in dynamic equilibrium: $${\mathrm{PbI}}_2(s)\rightleftarrows {\mathrm{Pb}}^{2+}(aq)+2{\mathrm{I}}^{-}(aq)$$

Consider the following redox reaction: ${\mathrm{IO}}_4^{-}(aq)+2{\mathrm{I}}^{-}(aq)+{\mathrm{H}}_2\mathrm{O}(l)$ ${\mathrm{I}}_2(s)+{\mathrm{IO}}_3^{-}(aq)+2{\mathrm{OH}}^{-}(aq)$ When ${\mathrm{KIO}}_4$ is added to a solution containing iodide ions labeled with radioactive iodine-128, all the radioactivity appears in ${\mathrm{I}}_2$ and none in the ${\mathrm{IO}}_3^{-}$ ion. What can you deduce about the mechanism for the redox process?

Explain how you might use a radioactive tracer to show that ions are not completely motionless in crystals.

List the factors that affect the intensity of radiation from a radioactive element.

What are rad and rem, and how are they related?

Explain, with examples, the difference between somatic and genetic radiation damage.

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 years. Calculate how long (in years) it will take for $1.00\mathrm{g}$ of the isotope to be reduced to $0.200\mathrm{g}$ by decay.

Nuclei with an even number of protons and an even number of neutrons are more stable than those with an odd number of protons and/or an odd number of neutrons. What is the significance of the even numbers of protons and neutrons in this case?

Tritium $\left({}^3\mathrm{H}\right)$ is radioactive and decays by electron emission. Its half-life is 12.5 years. In ordinary water the ratio of ${}^1\mathrm{H}$ to ${}^3\mathrm{H}$ atoms is $1.0\times {10}^{17}$ to $1.$ (a) Write a balanced nuclear equation for tritium decay. (b) How many disintegrations will be observed per minute in a 1.00-kg sample of water?