The half-life for the radioactive decay of Ce-141 is 32.5

Problem 1SC Besides shielding, what other methods help reduce exposure to radiation?

Problem 2QP Identify the type of particle or radiation for each of the following: a. 0?1e b. 11H c. 10n

Problem 2SC Write a balanced nuclear equation for the alpha decay of Po-214.

Problem 3QP Naturally occurring potassium consists of three isotopes: potassium-39, potassium-40, and potassium-41. a. Write the atomic symbol for each isotope. b. In what ways are the isotopes similar, and in what ways do they differ?

Problem 3SC Write the balanced nuclear equation for the beta decay of chromium-51.

Problem 4QP Naturally occurring iodine is iodine-127. Medically, radioactive isotopes of iodine-125 and iodine-130 are used. a. Write the atomic symbol for each isotope. b. In what ways are the isotopes similar, and in what ways do they differ?

Problem 4SC Write the balanced nuclear equation for xenon-118, which undergoes positron emission.

Problem 5QP Supply the missing information in the following table: Medical Use Atomic Symbol Mass Number Number of Protons Number of Neutrons Heart imaging Radiation therapy 60 27 Abdominal scan 31 36 Hyperthyroidism Leukemia treatment 32 17

Problem 5SC The first radioactive isotope was produced in 1934 by the bombardment of aluminum-27 by an alpha particle to produce a radioactive isotope and one neutron. What is the balanced nuclear equation for this transmutation?

Problem 6QP Supply the missing information in the following table: Medical Use Atomic Symbol Mass Number Number of Protons Number of Neutrons Cancer treatment 13155Cs Brain scan 99 43 Blood flow 141 58 Bone scan 85 47 Lung function 13354Xe

Problem 33QP Strontium-85, used for bone scans, has a half-life of 65 days. How long will it take for the radiation level of strontium-85 to drop to one-fourth of its original level? To one-eighth?

Problem 34QP Fluorine-18, which has a half-life of 110 min, is used in PET scans (see Section 4.5). If 100. mg of fluorine-18 is shipped at 8 a.m., how many milligrams of the radioisotope are still active if the sample arrives at the radiology laboratory at 1:30 p.m.?

Problem 35QP Bone and bony structures contain calcium and phosphorus. a. Why would the radioisotopes calcium-47 and phosphorus-32 be used in the diagnosis and treatment of bone diseases? b. The radioisotope strontium-89, a beta emitter, is used to treat bone cancer. Write the balanced nuclear equation and explain why a strontium radioisotope would be used to treat bone cancer.

Problem 36QP a.Technetium-99m emits only gamma radiation. Why would this type of radiation be used in diagnostic imaging rather than an isotope that also emits beta or alpha radiation? b. A person with polycythemia vera (excess production of red blood cells) receives radioactive phosphorus-32. Why would this treatment reduce the production of red blood cells in the bone marrow of the patient?

Problem 37QP In a diagnostic test for leukemia, a person receives 4.0 mL of a solution containing selenium-75. If the activity of the selenium-75 is 45 ?Ci/mL, what dose, in microcuries, does the patient receive?

Problem 38QP A vial contains radioactive iodine-131 with an activity of 2.0 mCi/mL. If a thyroid test requires 3.0 mCi in an “atomic cocktail,” how many milliliters are used to prepare the iodine-131 solution?

Problem 39QP What is nuclear fission?

Problem 40QP How does a chain reaction occur in nuclear fission?

Problem 41QP Complete the following fission reaction:

Problem 42QP In another fission reaction, uranium-235 bombarded with a neutron produces strontium-94, another small nucleus, and three neutrons. Write the balanced nuclear equation for the fission reaction.

Problem 73CQ A 64-?Ci sample of Tl-201 decays to 4.0 ?Ci in 12 days. What is the half-life, in days, of Tl-201? (4.4)

Problem 74CQ A 16-?g sample of sodium-24 decays to 2.0 ?g in 45 h. What is the half-life, in hours, of sodium-24?

Problem 75CQ The activity of K-40 in a 70.-kg human body is estimated to be 120 nCi. What is this activity in becquerels? (4.3)

Problem 76CQ The activity of C-14 in a 70.-kg human body is estimated to be 3.7 kBq. What is this activity in microcuries? (4.3)

Problem 77CQ Write a balanced equation for each of the following radioactive emissions: (4.2) a. an alpha particle from Hg-180 b. a beta particle from Au-198 c. a positron from Rb-82

Problem 78CQ Write a balanced equation for each of the following radioactive emissions: (4.2) a. an alpha particle from Gd-148 b. a beta particle from Ni-64 c. a positron from Al-25

Problem 79CQ All the elements beyond uranium, the transuranium elements, have been prepared by bombardment and are not naturally occurring elements. The first transuranium element, neptunium, Np, was prepared by bombarding U-238 with neutrons to form a neptunium atom and a beta particle. Complete the following equation: (4.2) 10n + 23892U ? ? + ?

Problem 80CQ One of the most recent transuranium elements, ununoctium-294 (Uuo-294), atomic number 118, was prepared by bombarding californium-249 with another isotope. Complete the following equation for the preparation of this new element: (4.2) ? + 24998Cf ? 294118Uuo + 310n

Problem 13QP Write a balanced nuclear equation for the alpha decay of each of the following radioactive isotopes: a. b. c. d. radon-220

Problem 14QP Write a balanced nuclear equation for the alpha decay of each of the following radioactive isotopes: a. curium-243 b. c. d.

Problem 15QP Write a balanced nuclear equation for the beta decay of each of the following radioactive isotopes: a. 2511Na b. 208O c. strontium-92 d. iron-60

Problem 16QP Write a balanced nuclear equation for the beta decay of each of the following radioactive isotopes: a. 4419K b. iron-59 c. potassium-42 d. 14156Ba

Problem 17QP Write a balanced nuclear equation for the positron emission of each of the following radioactive isotopes: a. silicon-26 b. cobalt-54 c. d.

Problem 18QP Write a balanced nuclear equation for the positron emission of each of the following radioactive isotopes: a. boron-8 b. 158O c. 4019K d. nitrogen-13

Problem 19QP Complete each of the following nuclear equations and describe the type of radiation: a. 2813Al ? ? + 0?1e b. 180m73Ta ? 18073Ta + ? c. 6629Cu ? 6630Zn + ? d. ? ? 23490Th + 42He e. 18080Hg ? ? + 0+1e

Problem 20QP Complete each of the following nuclear equations and describe the type of radiation: a. 116C ? 115B + ? b. 3516S ? ? + 0?1e c. ? ? 9039 + 0?1e d. 21083Bi ?? + 42He e. ? ? 8939Y + 0+1e

Complete each of the following bombardment reactions: a. \({ }_{0}^{1} n+{ }_{4}^{9} \mathrm{Be} \longrightarrow \text { ? }\) b. \({ }_{0}^{1} n+{ }_{52}^{131} \mathrm{Te} \longrightarrow ?+{ }_{-1}^{0} e\) c. \({ }_{0}^{1} n+? \longrightarrow{ }_{11}^{24} \mathrm{Na}+{ }_{2}^{4} \mathrm{He}\) d. \({ }_{2}^{4} \mathrm{He}+{ }_{13}^{27} \mathrm{Al} \longrightarrow ?+{ }_{0}^{1} n\)

Problem 22QP Complete each of the following nuclear equations and describe the type of radiation: a. b. c. d.

Problem 53AQP Identify each of the following as alpha decay, beta decay, positron emission, or gamma emission: a. b. c.

Problem 54AQP Identify each of the following as alpha decay, beta decay, positron emission, or gamma emission: a. b. c.

Problem 55AQP Write a balanced nuclear equation for each of the following: (4.2) a. Th-225 (? decay) b. Bi-210 (? decay) c. cesium-137 (? decay) d. tin-126 (? decay) e. F-18 (?+ emission)

Problem 56AQP Write the balanced nuclear equation for each of the following: a. potassium-40 (? decay) b. sulfur-35 (? decay) c. platinum-190 (? decay) d. Ra-210 (? decay) e. In-113m (? emission)

Problem 57AQP Complete each of the following nuclear equations: (4.2) a. 42He + 147? ? + 11H b. 42He 2713Al ? 3014Si + ? c. 10n + 23592U ? 9038Sr + 310n + ? d. 23m12Mg ? ? + 00?

Problem 58AQP Complete each of the following nuclear equations: (4.2) a. ? + 5927Co ? 5625Mn + 42He b. ? ? 147N + 0?1e c. 0?1e + 7636Kr ? ? d. 42He + 24195Am ? ? + 210n

Problem 59AQP Write the balanced nuclear equation for each of the following: (4.2) a. When two oxygen-16 atoms collide, one of the products is an alpha particle. b. When californium-249 is bombarded by oxygen-18, a new isotope and four neutrons are produced. c. Radon-222 undergoes alpha decay.

Problem 60AQP Write the balanced nuclear equation for each of the following: (4.2) a. Polonium-210 decays to give lead-206. b. Bismuth-211 emits an alpha particle. c. A radioisotope emits a positron to form titanium-48.

Problem 61AQP If the amount of radioactive phosphorus-32 in a sample decreases from 1.2 mg to 0.30 mg in 28.6 days, what is the half-life, in days, of phosphorus-32? (4.4)

If the amount of radioactive iodine-123 in a sample decreases from 0.4 g to 0.1 g in 26.4 h, what is the half-life, in hours, of iodine-123? (4.4)

Problem 6SC If P-32 is a beta emitter, how do the number of rems compare to the rads?

Problem 7QP Write the symbol for each of the following isotopes used in nuclear medicine: a. copper-64 b. selenium-75 c. sodium-24 d. nitrogen-15

Problem 7SC Fe-59 has a half-life of 44 days. If a laboratory received 8.0 µg of Fe-59, how many micrograms of Fe-59 are still active after 176 days?

Problem 8QP Write the symbol for each of the following isotopes used in nuclear medicine: a. indium-111= b. palladium-103= c. barium-131= d. rubidium-82

Problem 8SC Suppose that a piece of wood found in a tomb had 8 of its original carbon-14 activity. About how many years ago was the wood part of a living tree?

Problem 10QP Identify each of the following:

Problem 9QP Identify each of the following:

An experimental treatment uses boron-10, which is taken up by malignant tumors. When bombarded with neutrons, boron-10 decays by emitting alpha particles that destroy the surrounding tumor cells. Write the balanced equation for the nuclear reaction for this experimental procedure.

Problem 11QP Match the type of radiation with each of the following statements: 1. alpha particle 2. beta particle 3. gamma radiation a. does not penetrate skin b. shielding protection includes lead or thick concrete c. can be very harmful if ingested

Problem 12QP Match the type of radiation with each of the following statements: 1. alpha particle 2. beta particle 3. gamma radiation a. penetrates farthest into skin and body tissues b. shielding protection includes lab coats and gloves c. travels only a short distance in air

Indicate whether each of the following is characteristic of the fission or fusion process, or both: a. Neutrons bombard a nucleus. b. The nuclear process occurs in the Sun. c. A large nucleus splits into smaller nuclei.d. Small nuclei combine to form larger nuclei.

Problem 45UTC Draw the new nucleus when this isotope emits a positron to complete the following figure: (4.2)

Problem 44QP Indicate whether each of the following is characteristic of the fission or fusion process, or both: a. Very high temperatures are required to initiate the reaction b. Less radioactive waste is produced. c. Hydrogen nuclei are the reactants. d. Large amounts of energy are released when the nuclear reaction occurs.

Problem 46UTC A nucleus is shown with protons and neutrons. proton neuton Draw the nucleus that emits a beta particle to complete the following figure:

Problem 47UTC A nucleus is shown with protons and neutrons. proton neuton Draw the nucleus of the isotope that is bombarded in the Following figure:

Problem 48UTC A nucleus is shown with protons and neutrons. proton neuton Complete the following bombardment reaction by drawing the nucleus of the new isotope that is produced in the following figure:

Problem 49UTC A nucleus is shown with protons and neutrons. proton neuton Carbon dating of small bits of charcoal used in cave paintings has determined that some of the paintings are from 10 000 to 30 000 y old. Carbon-14 has a half-life of 5730 y. In a 1 ?g-sample of carbon from a live tree, the activity of carbon-14 is 6.4 ?Ci. If researchers determine that 1 ?g of charcoal from a prehistoric cave painting in France has an activity of 0.80 ?Ci, what is the age of the painting? The technique of carbon dating is used to determine the age of ancient cave paintings.

Problem 50UTC A nucleus is shown with protons and neutrons. proton neuton Use the following decay curve for iodine-131 to answer Questions a-c: a. Complete the values for the mass of radioactive iodine-131 on the vertical axis. b. Complete the number of days on the horizontal axis. c. What is the half-life, in days, of iodine-131?

Problem 51AQP Give the number of protons and number of neutrons in the nucleus of each the following: a. sodium-25 b. nickel-61 c. rubidium-84 d. silver-110

Give the number of protons and number of neutrons in the nucleus of each of the following: a. boron-10 b. zinc-72 c. iron-59 d. gold-198

Problem 1QP Identify the type of particle or radiation for each of the following: a. 42He b. 0+1e c. 00?

Problem 23QP Match each property (1–3) with its unit of measurement. 1. activity 2. absorbed dose 3. biological damage a. rad b. mrem c. µCi d. Gy

Problem 24QP Match each property (1–3) with its unit of measurement. 1. activity 2. absorbed dose 3. biological damage a. mrad b. gray c. becquerel d. Sv

Problem 25QP Two technicians in a nuclear laboratory were accidentally exposed to radiation. If one was exposed to 8 mGy and the other to 5 rad, which technician received more radiation?

Problem 27QP a. The recommended dosage of iodine-131 is 4.20 µCi/kg of body mass. How many microcuries of iodine-131 are needed for a 70.0-kg patient with hyperthyroidism? b. A person receives 50 rad of gamma radiation. What is that amount in grays?

Problem 26QP Two samples of a radioisotope were spilled in a nuclear laboratory. The activity of one sample was 8 kBq and the other 15 µCi. Which sample produced the higher amount of radiation?

Problem 28QP a. The dosage of technetium-99m for a lung scan is 20. µCi/kg of body mass. How many millicuries of technetium-99m are needed for a 50.0-kg patient? b. Suppose a person absorbed 50 mrad of alpha radiation. What would be the equivalent dose in millirems?

For each of the following, indicate if the number of half-lives elapsed is: 1. one half-life 2. two half-lives 3. three half-lives a. a sample of Ce-141 with a half-life of 32.5 days after 32.5 days b. a sample of F-18 with a half-life of 110 min after 330 min c. a sample of Au-198 with a half-life of 2.7 days after 5.4 days

Problem 29QP For each of the following, indicate if the number of half-lives elapsed is: 1. one half-life 2. two half-lives 3. three half-lives a. a sample of Pd-103 with a half-life of 17 days after 34 days b. a sample of C-11 with a half-life of 20 min after 20 min c. a sample of At-211 with a half-life of 7 h after 21 h

Problem 31QP Technetium-99m is an ideal radioisotope for scanning organs because it has a half-life of 6.0 h and is a pure gamma emitter. Suppose that 80.0 mg were prepared in the technetium generator this morning. How many milligrams of technetium-99m would remain after the following intervals? a. one half-life b. two half-lives c. 18 h d. 24 h

Problem 32QP A sample of sodium-24 with an activity of 12 mCi is used to study the rate of blood flow in the circulatory system. If sodium-24 has a half-life of 15 h, what is the activity of the sodium after 2.5 days?

Problem 63AQP Calcium-47, a beta emitter, has a half-life of 4.5 days. (4.2, 4.4) a. Write the balanced nuclear equation for the beta decay of calcium-47. b. How much, in milligrams, of a 16-mg sample of calcium-47 remains after 18 days? c. How many days have passed if 4.8 mg of calcium-47 decayed to 1.2 mg of calcium-47?

Problem 64AQP Cesium-137, a beta emitter, has a half-life of 30 y. (4.2, 4.4) a. Write the balanced nuclear equation for the beta decay of cesium-137. b. How many grams of a 16-mg sample of cesium-137 would remain after 90 y? c. How many years are required for 28 mg of cesium-137 to decay to 3.5 mg of cesium-137?

Problem 65AQP A thyroid scan used 320 mCi of I-123, which has a half-life of 13.2 h. How long, in hours, would it take for the activity to be reduced to 40. mCi? (4.4)

Problem 66AQP A wooden object from the site of an ancient temple has a carbon-14 activity of 10 counts/min compared with a reference piece of wood cut today that has an activity of 40 counts/min. If the half-life for carbon-14 is 5730 y, what is the age of the ancient wood object?

Problem 67AQP A 120-mg sample of technetium-99m is used for a diagnostic test. If technetium-99m has a half-life of 6.0 h, how many milligrams of the technetium-99m sample remains active 24 h after the test?

Problem 68AQP The half-life of oxygen-15 is 124 s. If a sample of oxygen-15 has an activity of 4000 Bq, how many minutes will elapse before it has an activity of 500 Bq?

Problem 69CQ Uranium-238 decays in a series of nuclear changes until stable lead-206 is produced. Complete the following nuclear equations that are part of the uranium-238 decay series: a. b. c.

Problem 70CQ The iceman known as Ötzi was discovered in a high mountain pass on the Austrian-Italian border. Samples of his hair and bones had carbon-14 activity that was 50% of that present in new hair or bone. Carbon-14 undergoes beta decay and has a half-life of 5730 y. The mummified remains of Ötzi were discovered in 1991. a. How long ago did Ötzi live? b. Write a balanced nuclear equation for the decay of carbon-14.

Problem 71CQ The half-life for the radioactive decay of Ce-141 is 32.5 days. If a sample has an activity of 4.0 ?Ci after 130 days have elapsed, what was the initial activity, in microcuries, of the sample? (4.4)

Problem 72CQ A technician was accidentally exposed to potassium-42 while doing some brain scans for possible tumors. The error was not discovered until 36 h later when the activity of the potassium-42 sample was 2.0 ?Ci. If potassium-42 has a half-life of 12 h, what was the activity of the sample at the time the technician was exposed? (4.4)