Chemistry nuclear

2 Nuclear Stability Patterns of Nuclear Stability Nuclear Binding Energy  

3 Natural Radioactivity Kinetics of Radioactive Decay Dating Based on Radioactive Decay n 

7 Uses of Isotopes Chemical Analysis Isotopes in Medicine Wt 

The highly energetic particles produced by this reaction destroy the tumor cells in which the °B is concentrated. Because the particles are confined to just a few micrometers, they preferentially destroy tumor cells without damaging neighboring normal cells. 

BNCT is a highly promising treatment and is an active area of research. One of the major goals of the research is to develop suitable compounds to deliver °B to the desired site. For such a compound to be effective, it must meet several criteria. It must have a high affinity for tumor cells, be able to pass through membrane barriers to reach the tumor site, and have minimal toxic effects on the human body. 

Nuclear chemistry has a vast range of applications, from the production of electricity to the diagnosis and treatment of diseases. 

EHEJiES Unstable nuclei can break apart spontaneously, changing the identity of atoms. 

EHEKES Fission—the splitting of nuclei—and fusion—the combining of nuclei—release tremendous amounts of energy. 

Nuclear reactions have many useful applications, but they also have harmful biological effects. 

When the products of one nuclear reaction cause additional nuclear reactions to occur, the resulting chain reaction can release large amounts of energy in a short period of time. Explore chain reactions by modeling them with dominoes. 

1 Nuclear Chemistry Is the Study of Changes Involving Atomic Nuclei 856 

2 The Stability of a Nucleus Is Determined Primarily by Its Neutron-to-Proton Ratio 860 

3 Radioactive Decay Is a First-Order Kinetic Process 867 

4 New Isotopes Can Be Produced Through the Process of Nuclear Transmutation 873 

5 In Nuclear Fission, a Large Nucleus Is Split into Smaller Nuclei 876 

1 RADIOACTIVITY AND NUCLEAR EQUATIONS We begin by learning how to describe nuclear reactions using equations analogous to chemical equations, in which the nuclear charges and masses of reactants and products are in balance. We see that radioactive nuclei most commonly decay by emission of alpha, beta, or gamma radiation. 

2 PATTERNS OF NUCLEAR STABILITY We see that nuclear stability is determined largely by the neutron-to-proton ratio. For stable nuclei, this ratio increases with increasing atomic number. All nuclei with 84 or more protons are radioactive. Heavy nuclei gain stability by a series of nuclear disintegrations leading to stable nuclei. 

3 NUCLEAR TRANSMUTATIONS We explore nuclear transmutations, which are nuclear reactions induced by bombardment of a nucleus by a neutron or an accelerated charged particle. 

4 RATES OF RADIOACTIVE DECAY We learn that radioisotope decays are first-order kinetic processes with characteristic half-lives. Decay rates can be used to determine the age of ancient artifacts and geological formations. 

5 DETECTION OF RADIOACTIVITY We see that the radiation emitted by a radioactive substance can be detected by a variety 

Stan is surrounded by nuclear changes that take place outside his body, as well. The soil under his house contains a small amount of uranium-238, which undergoes a type of nuclear reaction called alpha emission. A series of changes in the nucleus of the uranium-238 leads to an even smaller amount of radon-222, which is a gas that he inhales in every breath he takes at home. Subsequently, radon-222 undergoes a nuclear reaction very similar to the reaction for uranium-238. 

On Stan s way to the hospital, he passes a nuclear power plant that generates electricity for the homes and businesses in his city by means of yet another kind of nuclear reaction. When Stan gets to the hospital, Fred shows him the equipment he is using in his research. It is a positron emission tomography (PET) machine that allows Fred to generate images showing which parts of 

PET scans and MRI scans (like the one above) use changes in the nuclei of atoms to create an image of the soft tissues of the body. 

The presentation of information in this chapter assumes that you can already perform the tasks listed below. You can test your readiness to proceed by answering the Review Questions at the end of the chapter. This might also be a good time to read the Chapter Objectives, which precede the Review Questions. 

Describe the nuclear model of the atom, including the general location of the protons, neutrons, and electrons, the relative size of the nucleus compared to the size of the atom, and the modern description of the electron. (Seaion 2.4) 

The energy of the sun comes from nuclear reactions. Solar flares are an indication of fusion reactions occurring at a temperature of millions of degrees. 

Mass-Energy Relationship in Nuclear Reactions Transuranium Elements 

The AP exam requires you to know about nuclear equations, half-lives, radioactivity, and chemical applications of nuclear properties. This chapter begins with a brief review of the history of the nucleus and how we came to know about it and then moves into the required topics. 

Radioactive Isotopes Radioactive Emanations Separating Nuclear Emanations Nuclear Fusion and Fission Half-Life (t1/2) 

When the nucleus of an atom breaks down, three types of emanations are ejected from the unstable nucleus. These three particles are called alpha particles, beta particles, and gamma rays. These particles can be examined side by side in the chart below  

Type of Radiation Alpha Particles Beta Particles Gamma Rays 

Description Helium nucleus (not helium atom). Same properties as an electron but was ejected from the nucleus. Not a particle at all. Gamma rays are high-energy radiation. 

Our sun supplies enei to the earth from a distance of 93,000,000 miles. Like other stars, it is a giant nuclear fusion reactor. Much of its energy comes from the fusion of deuterium,, producing helium, He. 

22-7 Neutron-Poor Nuclei (Below the Band of Stability) 

22-8 Nuclei with Atomic Number Greater Than 83 

22-9 Detection of Rad iation 22-10 Rates of Decay and Half-Life 22-11 Decay Series 22-12 Uses of Radionuclides 22-13 Artificial Transmutations of Elements 22-14 Nuclear Fission 22-15 Nuclear Fission Reactors 22-16 Nuclear Fusion 

Unless otheiwise noted, all content on this page is Cengage Learning. 

John Howard Northrop was born into an academic family in Yonkers, New York, in 1891. He entered Columbia University in 1908, from which institution he received his Ph.D. in chemistry in 1915. In 1916 he was appointed to the Rockefeller Institute, and he remained there for the rest of his working life. In 1924 he transferred to the Princeton branch of the institute, where most of his significant work on proteins was performed. In 1949, when the institute closed its Princeton branch, Northrop moved to the University of Cafifomia at Berkeley as professor of bacteriology and biophysics, while remaining a member of the institute and continuing to receive its support for his work. He retired in 1959. He died in 1987, aged ninety-five, see also Hydrolysis Proteins. 

Herriott, R. M. (1983). John H. Northrop The Nature of Enzymes and Baeterio-phage. Trends in Biochemical Sciences. 13 296-297. 

Robbins, F. C. (1991). John Howard Northrop (5 July, 1891-May 27, 1987). Proceedings of the American Philosophical Society 135 315-320. 

Northrop, John. Nobel lecture. Available from http //www.nobel.se/chemistry/ 

There are essentially three sources of radioactive elements. Primordial nuclides are radioactive elements whose half-lives are comparable to the age of our solar system and were present at the formation of Earth. These nuclides are generally referred to as naturally occurring radioactivity and are derived from the radioactive decay of thorium and uranium. Cosmogenic nuclides are atoms that are constantly being synthesized from the bombardment of planetary surfaces by cosmic particles (primarily protons ejected from the Sun), and are also considered natural in their origin. The third source of radioactive nuclides is termed anthropogenic and results from human activity in the production of nuclear power, nuclear weapons, or through the use of particle accelerators. 

From its role in shaping world politics to its applications that produce electrical power and diagnose and treat disease, nuclear chemistry has profound effects upon the world in which we live. 

Visit the Chemistry Web site at chemistrymc.com to find links about nuclear chemistry. 

Many medical diagnostic tests and treatments involve the use of radioactive substances. Here, a radioactive substance known as a radiotracer is used to illuminate the carotid artery, which runs through the neck into the skull. 

Stand the individual dominoes on end and arrange them so that when the first domino falls, it causes the other dominoes to fall in series. 

Chemical reactions involve the interaction of the outer electrons of substances. As one substance changes into another, chemical bonds are broken and created as atoms rearrange. Atomic nuclei are not directly involved in chemical reactions, but they play a critical role in the behavior of matter. Typical chemical reactions involve the interaction of electrons in atoms, but nuclear reactions involve the atom s nucleus. The nucleus contains most of the atom s mass but occupies only a small fraction of its volume. Electrons have only about 1/2000 the mass of a nucleon. To put this in perspective, consider that if the nucleus were the size of a baseball, the mean distance to the nearest electrons would be over two miles. 

At the start of the twentieth century, it was discovered that the nucleus is composed of positively charged protons and neutral neutrons (see Chapter 4). These particles are collectively called nucleons. During the last half of the same century, scientists learned how to harness the power of the atom. The deployment of two atomic bombs brought a quick and dramatic end to World War II. This was followed by nuclear proliferation, the Cold War, and the current debate over 

Summary Radioactivity, the spontaneous decay of an unstable isotope to a more stable one, was first discovered by Henri Becquerel in 1896. Marie Curie and her husband expanded on his work and developed most of the concepts that are used today. 

You should read this chapter if you need to review or learn about  

Nuclear reactions Nuclear stability Half-lives (ti/2) 

Mass/energy conversions Nuclear fission and fusion Nuclear decay problems 

Copyright 2007 by John Moore and Richard Langley. Click here for terms of use. 

Thin-line arrows indicate fission-fragment decay paths. Panels (a)-(f) illustrate the regions around He, Ne, Ar, Kr, Xe, and Rn, respectively. 

If we understand nuclear chemistry to mean the study of the effects of nuclear transformations, especially of proton number (i.e., transformation of one element to another), then from the physicist s or chemist s viewpoint the nuclear chemistry of noble gases is neither more nor less interesting than any other group of elements, and there is no reason to distinguish noble gases from any other elements. From the geochemist s viewpoint, which defines the scope of this book, particular interest is attached to natural nuclear chemistry effects, which involve enough nuclear transformations to produce observable variations in elemental or, more commonly, 

Parent Half-life (Ga) Decay Daughter Yield 

Podosek et al., 1994 Takaoka et al., 1996) the discrepancy arises in geological interpretation rather than analytical uncertainties. f Fission produces several isotopes of both Xe and Kr (those with no stable isobars of lower atomic number) see Table 1.5 for yields and compositions. 

Parent Mode Branching Ratio Yield 136Xe (%) 86Kr References 

In the preceding chapters, we discuss chemical reactions essentially as rearrangements of atoms from one set of bonding partners to another set. We turn now to a different kind of reaction in which the elemental identity of the atomic nucleus changes in the course of the reaction. This is a fascinating subject that arose early in the 20th century from experimental studies of the physical structure of the atom (see Section 1.4). 

Spontaneous emission of radiation or particles by a nucleus undergoing decay - Radioactivity includes the emission of a particles, P particles, and y radiation. 

When a particles interact with matter, their speed is reduced and they are neutralized. 

Rapidly moving electrons, e , emitted by nuclei at speeds less than 90% of the speed of light Deflected by electric and magnetic fields, sometimes called negatrons 

When traveling between positively and negatively charged plates, a and P particles are deflected in opposite directions. 

High-energy photons (electromagnetic radiation) traveling at the speed of light Uncharged and not deflected by electric and magnetic fields Denoted by y or °y p particles 

This is one example of how nuclear chemistry is important in the treatment of cancer. 

In This Chapter, You Will Learn some of the fundamentals of nuclear chemistry and how nuclear reactions are important to living systems and to society. 

The CT scan shows a brain tumor that might be difficult or impossible to treat by conventional surgical methods. Nuclear medicine, including boron neutron capture therapy (BNCT), enables doctors to treat cancers of this type. 

a radiologist, begins by explaining the procedure for the CT scan to Luke and asking him if he has any allergies. Luke indicates that he has none, and Dr. Berns places an IV in Luke s arm. Dr. Berns then positions Luke into the scanner, and an initial scan of Luke s liver is taken. Dr. Berns then injects the first dose of contrast into Luke s bloodstream and a contrast scan is taken. From the CT scans, it is clear that a change in the liver tissue has occurred, possibly due to hepatitis or an infection. 

The liver has many functions and is critical to metabolism. The liver produces bile, consisting of bile salts and other chemicals, which is required for the digestion of lipids. The liver is also responsible for the conversion of waste products from protein metabolism into urea, which is eliminated in the urine. 

A patient may be given radioactive tracers such as technetium-99m, iodine-131, gallium-67, and thallium-201 that emit gamma radiation, which is detected and used to develop an image of the kidneys or thyroid or to follow the blood flow in the heart muscle. Radiologists must be knowledgeable about radiation exposure to limit the amount of radiation to which patients are exposed. 

With the production of artificial radioactive substances in 1934. the field of nuclear medicine was established. In 1937, the first radioactive isotope was used to treat a person with leukemia at the University of California at Berkeley. Major strides in the use of radioactivity in medicine occurred in 1946, when a radioactive iodine isotope was successfully used to diagnose thyroid function and to treat hyperthyroidism and thyroid cancer. Radioactive substances are now used to produce images of organs, such as liver, spleen, thyroid gland, kidneys, and the brain, and to detect heart disease. Today, procedures in nuclear medicine provide information about the function and structure of every organ in the body, which allows the nuclear physician to diagnose and treat diseases early. 

Describe alpha, beta, positron, and gamma radiation. 

I mention very little about the nucleus of the atom because, to a very large degree, it s not involved in chemical reactions. 

But in this chapter, I do discuss the nucleus and the changes it can undergo. 1 talk about radioactivity and the different ways an atom can decay. I discuss half-lives and show you how they re used in archeology. 1 also discuss nuclear fission and the hope that nucleeir fusion holds for humankind. Finally, you get a quick glimpse of how radiation affects the cells in your body. Don t forget the lead shielding  

To understand nuclear chemistry, you need to know the basics of atomic structure. Chapter 2 goes on and on about atomic structure, if you re interested. This section just provides a quickie brain dump. 

In the figure, X represents the symbol of the element found on the periodic table, Z represents the atomic number (the number of protons in the nucleus), and A represents the mass number (the sum of the protons and neutrons in that particular isotope). If you subtract the atomic number from the mass number (A - Z), you get the number of neutrons in that particular isotope. A short way to show the same information is to simply use the element symbol (X) and the mass number (A) — for excimple, U-235. 

Dealing With a Nuclear Breakup Balancing Reactions 

Luke has been experiencing weight loss, loss of appetite, vomiting, and some abdominal pain. Luke visits his doctor, who suspects a problem with his liver. The doctor orders blood work to be completed, and also refers Luke to a radiation technologist for a CT scan. Computed tomography, more commonly known as CT, uses X-rays to obtain a series of two-dimensional images and is commonly used for the diagnosis of abdominal diseases. 

Counting Protons and Neutrons (4.4) Writing Atomic Symbols for Isotopes (4.5) 

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In nuclear chemistry, a fission reaction (see atomic energy) may be initiated by a neutron and may also result in the production of one or more neutrons, which if they reacted in like manner could start a chain reaction. Normally, moderators such as cadmium rods which absorb neutrons are placed In the reactor to control the rate of fission. 

All of the forces in chemistry except for nuclear chemistry are electrical Opposite charges attract like charges repel This simple fact can take you a long way... 

Another area where controlled-potential coulometry has found application is in nuclear chemistry, in which elements such as uranium and polonium can be determined at trace levels. Eor example, microgram quantities of uranium in a medium of H2SO4 can be determined by reducing U(VI) to U(IV) at a mercury working electrode. 

Elemental boron is used in very diverse industries from metallurgy (qv) to electronics. Other areas of appHcation include ceramics (qv), propulsion, pyrotechnics, and nuclear chemistry. Boron is nontoxic. Workplace hygienic practices, however, include a voiding the breathing of boron dust or fine powder. 

G. F. Mailing and E. Von H.a]le,Merocfnamic Isotope Separation Processes for Cranium Enrichment Process Requirement, paper presented at the Symposium on New Advances ia Isotope Separation, Div. of Nuclear Chemistry and Technology, American Chemical Society, San Francisco, Calif., Aug. 1976 CCC-ND Report K/OM-2872, Oak Ridge Gaseous Diffusion Plant, Oak Ridge, Term., Oct. 7, 1976. 

Institute of Nuclear Chemistry and Technology 03-195 Warsaw, Dorodna 16, bdanko ichtj. waw.pl... 

Radiochemistry and Nuclear Chemistry, Second edition Rydborg, Chopin and Liljentzen... 

T. Siyam Nuclear Chemistry Department, Hot Laboratory Centre, Atomic Energy Authority, Cairo, Egypt... 

In 1921, Irene Curie (1897-1956) began research at the Radium Institute. Five years later she married Frederic Joliot (1900-1958). a brilliant young physicist who was also an assistant at the Institute. In 1931, they began a research program in nuclear chemistry that led to several important discoveries and at least one near miss. The Joliot-Curies were the first to demonstrate induced radioactivity. They also discovered the positron, a particle that scientists had been seeking for many years. They narrowly missed finding another, more fundamental particle, the neutron. That honor went to James Chadwick in England. In 1935,... 

We would like to thank all of the participants and contributors for their interest and cooperation, and the officers of the Division of Nuclear Chemistry and Technology, particularly the chairman, Richard Hahn, for... 

Chalmers University of Technology, Department of Nuclear Chemistry, S-41296 Goteborg, Sweden... 

Choppin, G. Rydberg, J. "Nuclear Chemistry. Theory and Applications" Pergamon Press London, 1980. 

Mass Spectrometry in Nuclear Chemistry H. G. Thode. C. C. McMullen, and K, Fritze... 

Department of Inorganic and Nuclear Chemistry School of Chemistry University of New South Wales Sydney, NSW 2052, Australia E-mail i.dance unsw.edu.au... 

Some isotopes that occur in nature are unstable and are said to be radioactive. A few radioactive isotopes, such as uranium-238 and carbon-14, are found on Earth, and many others can be synthesized in nuclear chemistry laboratories, as we describe in Chapter 22. Over time, radioactive isotopes decompose into other stable isotopes. Unstable isotopes decompose in several ways. Most nuclei that have Z > 83 decompose by giving off a helium... 

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