Chapter 24

A List the different types of radiation and their charges

Explain how you know whether the reaction is chemical or nuclear when an atom undergoes a reaction and attains a more-stable form.

Calculate Table 24.2 gives approximate energy values in units of MeV. Convert each value into joules using the following conversion factor \(1 \mathrm{MeV}=1.6 \times 10^{-13} \mathrm{J}\)

Write a balanced nuclear equation for the reaction in which oxygen-15 undergoes positron emission.

Thorium-229 is used to increase the lifetime of fluorescent bulbs. What type of decay occurs when thorium-229 decays to form radium-225?

Bandages can be sterilized by exposure to gamma radiation from cobalt-60, which has a half-life of 5.27 y. How much of a 10.0-mg sample of cobalt-60 is left after one half-life? Two half-lives? Three half-lives?

If the passing of five half-lives leaves 25.0 mg of a strontium-90 sample, how much was present in the beginning?

A Describe what happens to unstable nuclei.

Explain how you can predict whether or not an isotope is likely to be stable if you know its number of neutrons and protons.

Describe the forces acting on the particles within a nucleus and explain why neutrons are the glue holding the nucleus together.

Predict the nuclear equation for the alpha decay of radium-226 used on the tips of older lightning rods.

Calculate how much of a 10.0-g sample of americium-241 remains after four half-lives. Americium-241 is a radioisotope commonly used in smoke detectors and has a half-life of 430 y.

Calculate After 2.00 y, 1.986 g of a radioisotope remains from a sample that had an original mass of 2.000 \(\mathrm{g}\) . a. Calculate the half-life. b. How much of the radioisotope remains after 10.00 y?

Graph A sample of polonium-214 originally has a mass of 1.0 g. Express the mass remaining as a percent of the original sample after a period of one, two, and three half-lives. Graph the percent remaining versus the number of half- lives. Approximately how much time has elapsed when 20% of the original sample remain?

Write the balanced nuclear equation for the induced transmutation of aluminum-27 into sodium-24 by neutron bombardment. An alpha particle is released in the reaction.

Write the balanced nuclear equation for the alpha-particle bombardment of \(_{94}^{239} \mathrm{Pu}\) . One of the reaction products is a neutron.

Compare and contrast nuclear fission and nuclear fusion reactions. Describe the particles that are involved in each type of reaction and the changes they undergo.

Describe the process that occurs during a nuclear chain reaction and explain how to monitor a chain reaction in a nuclear reactor.

Explain how nuclear fission can be used to generate electric power.

Formulate an argument supporting or opposing nuclear power as your state’s primary power source. Assume the primary source of power currently is the burning of fossil fuels.

Calculate What is the energy change \((\Delta E)\) associated with a change in mass \((\Delta m)\) of 1.00 \(\mathrm{mg}\) ?

Explain one way in which nuclear chemistry is used to diagnose or treat disease.

Describe several methods used to detect and measure radiation.

Compare and contrast somatic and genetic biological damage

Explain why it is safe to use radioisotopes to diagnose medical problems

Calculate A lab worker receives an average radiation dose of 21 mrem each month. Her allowed dose is 5,000 mrem/y. On average, what fraction of her yearly dose does she receive?

Compare and contrast chemical reactions and nuclear reactions in terms of energy changes and the particles involved.

Match each numbered choice on the right with the correct radiation type on the left $$ \begin{array}{ll}{\text { a. alpha }} & {\text { 1. high-speed electrons }} \\\ {\text { b. beta }} & {\text { 2. } 2+\text { charge, blocked easily }} \\\ {\text { c. gamma }} & {\text { 3. no charge, electromagnetic radiation }}\end{array} $$

What is the difference between X rays and gamma rays?

Dental crown Uranium-234 is used to make dental crowns appear brighter. The alpha decay of uranium234 produces what isotope?

Detecting Material Flaws Flaws in welded metal parts of airplanes can be identified by placing the isotope iridium-192 on one side of the weld and photographic film on the other side to detect gamma rays that pass through. How does the gamma ray emission affect the atomic number and mass number of the iridium?

Colored Glass Thorium-230 can be used to provide coloring in glass objects. One method of producing thorium-230 is through the radioactive decay of actinium-230. Is this an example of alpha decay or beta decay? How do you know?

Plastic Bags Thin sheets of plastic are used to make items such as grocery bags. The sheets move under a source of promethium-147, emitting beta particles. The radiation intensity, measured under the plastic sheets, is used to monitor the thickness of the plastic. During this process, promethium changes into which element?

What is the strong nuclear force? On which particles does it act?

Explain the difference between positron emission and electron capture.

What is the significance of the band of stability?

What is a radioactive decay series? When does it end?

Radioisotopes What are the factors that determine the amount of a given radioisotope in nature?

Carbon-14 Dating Carbon-14 dating makes use of a specific ratio of two different radioisotopes. Define the ratio used in carbon-14 4 dating. Why is this ratio constant in living organisms?

Calculate the neutron-to-proton ratio for each atom a. \(\operatorname{tin}-134\) b. silver-107 c. carbon- 12 d. carbon- 14

Complete the following equations. $$a.\quad_{83}^{214} \mathrm{Bi} \rightarrow_{2}^{4} \mathrm{He}+?$$ $$b.\quad_{93}^{239} \mathrm{Np} \rightarrow_{94}^{239} \mathrm{Pu}+?$$

Write a balanced nuclear equation for the alpha decay of americium-241.

Write a balanced nuclear equation for the beta decay of cesium-137.

Bone Formation The electron capture of strontium-85 can be used by physicians to study bone formation. Write a balanced nuclear equation for this reaction.

Nuclear mishap The half-life of tritium \(\left(_{1}^{3} \mathrm{H}\right)\) is 12.3 \(\mathrm{y}\) If 48.0 \(\mathrm{mg}\) of tritium is released from a nuclear power plant during the course of a mishap, what mass of the nuclide will remain after 49.2 \(\mathrm{y} ?\) After 98.4 \(\mathrm{y} ?\)

Static Charge Static charge can interfere with the production of plastic products by attracting dust and dirt. To reduce it, manufacturers expose the area to polonium-210, which has a half-life of 138 days. How much of a 25.0-g sample will remain after one year (365 days)?

The half-life of polonium-218 is 3.0 min. If you start with 20.0 g, how long will it be before only 1.0 g remains?

An unknown radioisotope exhibits 8540 decays per second. After 350.0 min, the number of decays has decreased to 1250 per second. What is the half-life?

Define transmutation. Are all nuclear reactions also transmutation reactions? Explain.

What is a chain reaction? Give an example of a nuclear chain reaction.