<p>Baird Chem in Your life Chapter 17</p><p>1. What particles in an atom cause the same element to become an isotope? a. neutrons b. protons c. electrons d. photons a: Isotopes differ because of their mass numbers. If an isotope is the same element (same protons), then the neutrons are different.</p><p>2. What particle is released during beta emission? a. electron b. proton c. neutron d. photon a: Beta is defined as an electron on page 627.</p><p>3. When an isotope of lead (Pb-214) decays and releases a beta particle, what new particle forms? a. Pb-214 b. Bi-213 c. Bi-215 d. Tl-214 a: A beta particle is an electron that has an atomic number of −1 and 0 amu; therefore, it forms a particle with an atomic number of 83 and a mass number that stays the same.</p><p>4. What form of radiation is released when Th-232 forms Ra-228? a. alpha particle b. beta particle c. gamma radiation d. X-rays a: An alpha particle is an He-4 isotope; therefore, Th has an atomic number of 90 and forms Ra which has an atomic number of 88.</p><p>5. What particle forms when the isotope Bi-210 releases a beta particle? a. Po-210 b. Po-211 c. Pb-210 d. Pb-211 a: When Bi-210 loses a beta particle, an isotope of Po forms with a mass number of 210.</p><p>6. What isotope produces radon gas through disintegration? a. U-238 b. Th-234 c. Ra-226 d. Pb-206 a: See page 632 for the nuclear reactions that form radon gas.</p><p>7. If the half-life of radon is 3.8 days, what amount of a 20-gram sample of radioactive radon is left after 7.6 days? a. 5 grams b. 10 grams c. 15 grams d. none is left a: 7.6/3.8 = 2 half-life changes; therefore, a start amount of 20 grams will leave 10 grams during the first half-life change and 5 grams for the second half-life change.</p><p>8. How much I-131 has decayed after 32 days of a 90-gram sample if the half-life is 8 days? a. 75 g b. 70 g c. 60 g d. 80 g a: 32/8 = 4 half-life changes; therefore, 5 grams is still unstable. Subtract 5 grams from the original 80 grams, which equals 75 grams decayed.</p><p>9. What subatomic particle is required for fission to occur? a. neutron b. proton c. electron d. alpha particle a: This is described on page 635.</p><p>10. What isotope is usually used in fission reactors to produce energy? a. U-235 b. U-238 c. Pu-244 d. Ra-226 a: This is described on page 636.</p><p>11. What radioactive by-product is produced by the operation of nuclear power reactors? a. U-235 b. U-239 c. Np-239 d. Pu-239 a: This is described on page 637.</p><p>12. What country generates the largest proportion of electrical energy by nuclear power? a. France b. Japan c. United States d. Russia a: Table 17.1 on page 636 lists the countries that use nuclear power.</p><p>13. What isotopic element has the greatest potential as a producer of useful commercial energy? a. hydrogen b. helium c. lithium d. radium a: Hydrogen isotopes of deuterium and tritium are used for fusion reactors.</p><p>14. Which of the following is not a form of solar energy that can be transferred for commercial use? a. fuel cells b. wind power c. solar cells d. hydroelectric a: Fuel cells are chemical cells that have nothing to do with solar energy.</p><p>15. What materials are used for photovoltaic cells that produce electricity directly from sunlight? a. semiconductors b. conductors c. metals d. insulators a: Semiconductors are used in photovoltaic cells, as described on page 653.</p>