Which one of each pair of nuclides would you expect to have the longer half-life a

What is radioactivity? Who discovered it? How was it discovered?

Explain Marie Curies role in the discovery of radioactivity.

Define A , Z , and X in the following notation used to specify a nuclide: A ZX.

Use the notation from Question 3 to write symbols for a proton, a neutron, and an electron.

What is an alpha particle? What happens to the mass number and atomic number of a nuclide that emits an alpha particle?

What is a beta particle? What happens to the mass number and atomic number of a nuclide that emits a beta particle?

What is a gamma ray? What happens to the mass number and atomic number of a nuclide that emits a gamma ray?

What is a positron? What happens to the mass number and atomic number of a nuclide that emits a positron?

Describe the process of electron capture. What happens to the mass number and atomic number of a nuclide that undergoes electron capture?

Rank alpha particles, beta particles, positrons, and gamma rays in terms of: (a) increasing ionizing power; (b) increasing penetrating power.

Explain why the ratio of neutrons to protons (N>Z) is important in determining nuclear stability. How can you use the N>Z ratio of a nuclide to predict the kind of radioactive decay that it might undergo?

What are magic numbers? How are they important in determining the stability of a nuclide?

Describe the basic way that each device detects radioactivity: (a) film-badge dosimeter; (b) Geiger-Mller counter; and (c) scintillation counter.

Explain the concept of half-life with respect to radioactive nuclides. What rate law is characteristic of radioactivity?

Explain the main concepts behind the technique of radiocarbon dating. How can radiocarbon dating be corrected for changes in atmospheric concentrations of C-14? What range of ages can be reliably determined by C-14 dating?

How is the uranium to lead ratio in a rock used to estimate its age? How does this dating technique provide an estimate for Earths age? How old is Earth according to this dating method?

Describe fission. Include the concepts of chain reaction and critical mass in your description. How and by whom was fission discovered? Explain how fission can be used to generate electricity.

What was the Manhattan Project? Briefly describe its development and culmination.

Describe the advantages and disadvantages of using fission to generate electricity.

The products of a nuclear reaction usually have a different mass than the reactants. Why?

Explain the concepts of mass defect and nuclear binding energy. At what mass number does the nuclear binding energy per nucleon peak? What is the significance of this?

What is fusion? Why can fusion and fission both produce energy? Explain.

What are some of the problems associated with using fusion to generate electricity?

Explain transmutation and provide one or two examples.

How does a linear accelerator work? For what purpose is it used?

Explain the basic principles of cyclotron function.

How does radiation affect living organisms?

Explain why different kinds of radiation affect biological tissues differently, even though the amount of radiation exposure may be the same

Explain the significance of the biological effectiveness factor in measuring radiation exposure. What types of radiation would you expect to have the highest biological effectiveness factor?

Describe some of the medical uses, both in diagnosis and in treatment of disease, of radioactivity.

Write a nuclear equation for the indicated decay of each nuclide: a. U-234 (alpha) b. Th-230 (alpha) c. Pb-214 (beta) d. N-13 (positron emission) e. Cr-51 (electron capture)

Write a nuclear equation for the indicated decay of each nuclide: a. Po-210 (alpha) b. Ac-227 (beta) c. Tl-207 (beta) d. O-15 (positron emission) e. Pd-103 (electron capture)

Write a partial decay series for Th-232 undergoing the sequential decays: a, b, b, a.

Write a partial decay series for Rn-220 undergoing the sequential decays: a, b, b, a.

Fill in the missing particles in each nuclear equation. a. ____ h 217 85At + 4 2He b. 241 94Pu h 241 95Am + ____ c. 19 11Na h 19 10Ne + ____ d. 75 34Se + _____ h 75 33As

Fill in the missing particles in each nuclear equation. a. 241 95Am h 237 93Np + ____ b. _____ h 233 92U + 0 -1e c. 237 93Np h _____ + 4 2He d. 75 35Br h ____ + 0 +1e

Determine whether or not each nuclide is likely to be stable. State your reasons. a. Mg-26 b. Ne-25 c. Co-51 d. Te-124

Determine whether or not each nuclide is likely to be stable. State your reasons. a. Ti-48 b. Cr-63 c. Sn-102 d. Y-88

The first six elements of the first transition series have the following number of stable isotopes: Element Number of Stable Isotopes Sc 1 Ti 5 V 1 Cr 3 Mn 1 Fe 4 Explain why Sc, V, and Mn each has only one stable isotope while the other elements have several.

Neon and magnesium each has three stable isotopes while sodium and aluminum each has only one. Explain why this might be so

Predict a likely mode of decay for each unstable nuclide. a. Mo-109 b. Ru-90 c. P-27 d. Rn-196

Predict a likely mode of decay for each unstable nuclide. a. Sb-132 b. Te-139 c. Fr-202 d. Ba-123

Which one of each pair of nuclides would you expect to have the longer half-life? a. Cs-113 or Cs-125 b. Fe-62 or Fe-70

Which one of each pair of nuclides would you expect to have the longer half-life? a. Cs-149 or Cs-139 b. Fe-45 or Fe-52

One of the nuclides in spent nuclear fuel is U-235, an alpha emitter with a half-life of 703 million years. How long will take for the amount of U-235 to reach 10.0% of its initial amount?

A patient is given 0.050 mg of technetium-99m, a radioactive isotope with a half-life of about 6.0 hours. How long does it take for the radioactive isotope to decay to 1.0 * 10-3 mg ? (Assume no excretion of the nuclide from the body.)

A radioactive sample contains 1.55 g of an isotope with a half-life of 3.8 days. What mass of the isotope remains after 5.5 days? (Assume no excretion of the nuclide from the body.)

At 8:00 a.m., a patient receives a 58 mg dose of I-131 to obtain an image of her thyroid. If the nuclide has a half-life of 8 days, what mass of the nuclide remains in the patient at 5:00 p.m. the next day?

A sample of F-18 has an initial decay rate of 1.5 * 105 >s. How long will it take for the decay rate to fall to 2.5 * 103 >s? (F-18 has a half-life of 1.83 hours.)

A sample of Tl-201 has an initial decay rate of 5.88 * 104 >s. How long will it take for the decay rate to fall to 287>s? (Tl-201 has a half-life of 3.042 days.)

A wooden boat discovered just south of the Great Pyramid in Egypt has a carbon-14>carbon-12 ratio that is 72.5% of that found in living organisms. How old is the boat?

A layer of peat beneath the glacial sediments of the last ice age has a carbon-14>carbon-12 ratio that is 22.8% of that found in living organisms. How long ago was this ice age?

An ancient skull has a carbon-14 decay rate of 0.85 disintegrations per minute per gram of carbon ( 0.85 dis>min # g C ). How old is the skull? (Assume that living organisms have a carbon-14 decay rate of 15.3 dis>min # g C and that carbon-14 has a halflife of 5730 yr.)

A mammoth skeleton has a carbon-14 decay rate of 0.48 disintegrations per minute per gram of carbon ( 0.48 dis>min # g C ). When did the mammoth live? (Assume that living organisms have a carbon-14 decay rate of 15.3 dis>min # g C and that carbon-14 has a half-life of 5730 yr.)

A rock from Australia contains 0.438 g of Pb-206 to every 1.00 g of U-238. Assuming that the rock did not contain any Pb-206 at the time of its formation, how old is the rock?

A meteor has a Pb-206:U-238 mass ratio of 0.855:1.00. What is the age of the meteor? (Assume that the meteor did not contain any Pb-206 at the time of its formation.)

Write the nuclear reaction for the neutron-induced fission of U-235 to form Xe-144 and Sr-90. How many neutrons are produced in the reaction?

Write the nuclear reaction for the neutron-induced fission of U-235 to produce Te-137 and Zr-97. How many neutrons are produced in the reaction?

Write the nuclear equation for the fusion of two H-2 atoms to form He-3 and one neutron

Write the nuclear equation for the fusion of H-3 with H-1 to form He-4.

A breeder nuclear reactor is a reactor in which nonfissionable (nonfissile) U-238 is converted into fissionable (fissile) Pu-239. The process involves bombardment of U-238 by neutrons to form U-239, which then undergoes two sequential beta decays. Write nuclear equations for this process.

Write the series of nuclear equations to represent the bombardment of Al-27 with a neutron to form a product that subsequently undergoes an alpha decay followed by a beta decay

Rutherfordium-257 was synthesized by bombarding Cf-249 with C-12. Write the nuclear equation for this reaction.

Element 107, now named bohrium, was synthesized by German researchers by colliding bismuth-209 with chromium-54 to form a bohrium isotope and one neutron. Write the nuclear equation to represent this reaction.

If 1.0 g of matter is converted to energy, how much energy is formed?

A typical home uses approximately 1.0 * 103 kWh of energy per month. If the energy came from a nuclear reaction, what mass would have to be converted to energy per year to meet the energy needs of the home?

Calculate the mass defect and nuclear binding energy per nucleon of each nuclide. a. O@16 (atomic mass = 15.994915 amu) b. Ni@58 (atomic mass = 57.935346 amu) c. Xe@129 (atomic mass = 128.904780 amu)

Calculate the mass defect and nuclear binding energy per nucleon of each nuclide. a. Li@7 (atomic mass = 7.016003 amu) b. Ti@48 (atomic mass = 47.947947 amu) c. Ag@107 (atomic mass = 106.905092 amu)

Calculate the quantity of energy produced per gram of U-235 (atomic mass = 235.043922 amu) for the neutron-induced fission of U-235 to form Xe-144 ( atomic mass = 143.9385 amu ) and Sr-90 ( atomic mass = 89.907738 amu ) (discussed in Problem 57).

Calculate the quantity of energy produced per mole of U-235 (atomic mass = 235.043922 amu) for the neutron-induced fission of U-235 to produce Te-137 (atomic mass = 136.9253 amu) and Zr-97 (atomic mass = 96.910950 amu) (discussed in Problem 58).

Calculate the quantity of energy produced per gram of reactant for the fusion of two H-2 (atomic mass = 2.014102 amu) atoms to form He-3 (atomic mass = 3.016029 amu) and one neutron (discussed in Problem 59).

Calculate the quantity of energy produced per gram of reactant for the fusion of H-3 (atomic mass = 3.016049 amu) with H-1 (atomic mass = 1.007825 amu) to form He-4 (atomic mass = 4.002603 amu ) (discussed in Problem 60).

A 75 kg human is exposed to 32.8 rad of radiation. How much energy is absorbed by the persons body? Compare this energy to the amount of energy absorbed by the persons body if they jumped from a chair to the floor (assume that the chair is 0.50 m from the ground and that all of the energy from the fall is absorbed by the person).

If a 55-gram laboratory mouse is exposed to 20.5 rad of radiation, how much energy is absorbed by the mouses body?

PET studies require fluorine-18, which is produced in a cyclotron and decays with a half-life of 1.83 hours. Assuming that the F-18 can be transported at 60.0 miles>hour, how close must the hospital be to the cyclotron if 65% of the F-18 produced makes it to the hospital?

Suppose a patient is given 155 mg of I-131, a beta emitter with a half-life of 8.0 days. Assuming that none of the I-131 is eliminated from the persons body in the first 4.0 hours of treatment, what is the exposure (in Ci) during those first four hours?

Complete each nuclear equation and calculate the energy change (in J>mol of reactant) associated with each. (Be-9 = 9.012182 amu, Bi-209 = 208.980384 amu, He-4 = 4.002603 amu, Li-6 = 6.015122 amu, Ni-64 = 63.927969 amu, Rg-272 = 272.1535 amu, Ta-179 = 178.94593 amu, and W-179 = 178.94707 amu). a. _____ + 9 4Be h 6 3Li + 4 2He b. 209 83Bi + 64 28Ni h 272 111Rg + _____ c. 179 74W + _____ h 179 73Ta

Complete each nuclear equation and calculate the energy change (in J>mol of reactant) associated with each. (Al-27 = 26.981538 amu, Am-241 = 241.056822 amu, He-4 = 4.002603 amu, Np-237 = 237.048166 amu, P-30 = 29.981801 amu, S-32 = 31.972071 amu, and Si-29 = 28.976495 amu). a. 27 13Al + 4 2He h 30 15P + ____ b. 32 16S + ______ h 29 14Si + 4 2He c. 241 95Am h 237 93Np + _____

Write the nuclear equation for the most likely mode of decay for each unstable nuclide: a. Ru-114 b. Ra-216 c. Zn-58 d. Ne-31

Write the nuclear equation for the most likely mode of decay for each unstable nuclide: a. Kr-74 b. Th-221 c. Ar-44 d. Nb-85

Bismuth-210 is a beta emitter with a half-life of 5.0 days. If a sample contains 1.2 g of Bi-210 ( atomic mass = 209.984105 amu ), how many beta emissions occur in 13.5 days? If a persons body intercepts 5.5% of those emissions, to what dose of radiation (in Ci) is the person exposed?

Polonium-218 is an alpha emitter with a half-life of 3.0 minutes. If a sample contains 55 mg of Po-218 (atomic mass = 218.008965 amu), how many alpha emissions occur in 25.0 minutes? If the polonium is ingested by a person, to what dose of radiation (in Ci) is the person exposed?

Radium-226 ( atomic mass = 226.025402 amu ) decays to radon-224 (a radioactive gas) with a half-life of 1.6 * 103 years. What volume of radon gas (at 25.0 C and 1.0 atm) does 25.0 g of radium produce in 5.0 days? (Report your answer to two significant digits.)

In one of the neutron-induced fission reactions of U-235 ( atomic mass = 235.043922 amu ), the products are Ba-140 and Kr-93 (a radioactive gas). What volume of Kr-93 (at 25.0 C and 1.0 atm) is produced when 1.00 g of U-235 undergoes this fission reaction?

When a positron and an electron annihilate one another, the resulting mass is completely converted to energy. Calculate the energy associated with this process in kJ>mol.

A typical nuclear reactor produces about 1.0 MW of power per day. What is the minimum rate of mass loss required to produce this much energy?

Find the binding energy in an atom of 3 He, which has a mass of 3.016030 amu.

The overall hydrogen burning reaction in stars can be represented as the conversion of four protons to one a particle. Use the data for the mass of H-1 and He-4 to calculate the energy released by this process.

The nuclide 247Es can be made by bombardment of 238U in a reaction that emits five neutrons. Identify the bombarding particle.

The nuclide 6 Li reacts with 2 H to form two identical particles. Identify the particles.

The half-life of 238U is 4.5 * 109 yr. A sample of rock of mass 1.6 g produces 29 dis>s. Assuming all the radioactivity is due to 238U, find the percent by mass of 238U in the rock.

The half-life of 232Th is 1.4 * 1010 yr. Find the number of disintegrations per hour emitted by 1.0 mol of 232Th in 1 minute.

A 1.50 L gas sample at 745 mm Hg and 25.0 C contains 3.55% radon-220 by volume. Radon-220 is an alpha-emitter with a half-life of 55.6 s. How many alpha particles are emitted by the gas sample in 5.00 minutes?

A 228 mL sample of an aqueous solution contains 2.35% MgCl2 by mass. Exactly one-half of the magnesium ions are Mg-28, a beta emitter with a half-life of 21 hours. What is the decay rate of Mg-28 in the solution after 4.00 days? (Assume a density of 1.02 g>mL for the solution.)

When a positron and an electron collide and annihilate each other, two photons of equal energy are produced. Find the wavelength of these photons.

The half-life of 235U , an alpha emitter, is 7.1 * 108 yr. Calculate the number of alpha particles emitted by 1.0 mg of this nuclide in 1.0 minute.

Given that the energy released in the fusion of two deuterons to a 3 He and a neutron is 3.3 MeV, and in the fusion to tritium and a proton it is 4.0 MeV, calculate the energy change for the process 3 He + 1 n h 3 H + 1 p . Suggest an explanation for why this process occurs at much lower temperatures than either of the first two.

The nuclide 18F decays by both electron capture and b+ decay. Find the difference in the energy released by these two processes. The atomic masses are 18F = 18.000950 and 18O = 17.9991598 .

The space shuttle carries about 72,500 kg of solid aluminum fuel, which is oxidized with ammonium perchlorate according to the reaction shown here: 10 Al(s) + 6 NH4ClO4(s) h 4 Al2O3(s) + 2 AlCl3(s) + 12 H2O(g) + 3 N2(g) The space shuttle also carries about 608,000 kg of oxygen (which reacts with hydrogen to form gaseous water). a. Assuming that aluminum and oxygen are the limiting reactants, determine the total energy produced by these fuels. ( Hf for solid ammonium perchlorate is -295 kJ>mol. ) b. Suppose that a future space shuttle is powered by matter antimatter annihilation. The matter could be normal hydrogen (containing a proton and an electron) and the antimatter could be antihydrogen (containing an antiproton and a positron). What mass of antimatter is required to produce the energy equivalent of the aluminum and oxygen fuel currently carried on the space shuttle?

Suppose that an 85.0-gram laboratory animal ingests 10.0 mg of a substance that contained 2.55% by mass Pu-239, an alpha emitter with a half-life of 24,110 years. a. What is the animals initial radiation exposure in curies? b. If all of the energy from the emitted alpha particles is absorbed by the animals tissues, and if the energy of each emission is 7.77 * 10-12 J , what is the dose in rads to the animal in the fi rst 4.0 hours following the ingestion of the radioactive material? Assuming a biological effectiveness factor of 20, what is the 4.0-hour dose in rems?

In addition to the natural radioactive decay series that begins with U-238 and ends with Pb-206, there are natural radioactive decay series that begin with U-235 and Th-232. Both of these series end with nuclides of Pb. Predict the likely end product of each series and the number of a decay steps that occur.

The hydride of an unstable nuclide of a Group IIA metal, MH2(s) , decays by a-emission. A 0.025 mol sample of the hydride is placed in an evacuated 2.0 L container at 298 K. After 82 minutes, the pressure in the container is 0.55 atm. Find the half-life of the nuclide.

The nuclide 38Cl decays by beta emission with a half-life of 40.0 min. A sample of 0.40 mol of H38Cl is placed in a 6.24 L container. After 80.0 min the pressure is 1650 mmHg. What is the temperature of the container?

When BF3 is bombarded with neutrons, the boron undergoes an a decay, but the F is unaffected. A 0.20 mol sample of BF3 contained in a 3.0 L container at 298 K is bombarded with neutrons until half of the BF3 has reacted. What is the pressure in the container at 298 K?

Closely examine the diagram representing the beta decay of fluorine-21 and draw in the missing nucleus.

Approximately how many half-lives must pass for the amount of radioactivity in a substance to decrease to below 1% of its initial level?

Approximately how many half-lives must pass for the amount of radioactivity in a substance to decrease to below 1% of its initial level?

Identical amounts of two different nuclides, an alpha emitter and a gamma emitter, with roughly equal half-lives are spilled in a building adjacent to your bedroom. Which of the two nuclides poses the greater health threat to you while you sleep in your bed? If you accidentally wander into the building and ingest equal amounts of the two nuclides, which one poses the greater health threat?

Drugstores in many areas now carry tablets, under such trade names as Iosat and NoRad, designed to be taken in the event of an accident at a nuclear power plant or a terrorist attack that releases radioactive material. These tablets contain potassium iodide (KI). Can you explain the nature of the protection that they provide? ( Hint: see the label in the photo.)