Chapter 11 Nuclear Chemistry. 11 | 2 Nuclear Chemistry cont’d What is nuclear chemistry? The study of reactions that result from changes in the nucleus.

Chapter 11 Nuclear Chemistry

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Nuclear Chemistry cont’dWhat is nuclear chemistry?

The study of reactions that result from changes in the nucleus of an atom

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Nuclear Chemistry cont’dIn nuclear chemistry specific atoms are called……

……..nuclides.

Nuclides are identified by two types of notation:

1.Nuclear Symbol

2.Element name-mass number

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Nuclear Chemistry cont’d

N15

7

mass number

atomic number

This is an example of a nuclear symbol .

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Nuclear Chemistry cont’dThe nuclear symbol can also be expressed as shown.

mass number

nitrogen-15

name of element

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Nuclear Chemistry cont’dPractice Questions

Write two notations for a nuclidethat has:

a.41 protons, 41 electrons, 55 neutronsb.11 protons, 11 electrons, 14 neutrons

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Radioactive Decay

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Nuclides are either stable or unstable

Unstable nuclides (or radionuclides)undergo radioactive decay.

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Radioactive decay is a nuclear reaction that emits radiation while changing the nuclide of one element into another.

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For example; the silver- 113 radionuclide decays to cadmium- 113 with the emission of a beta particle and gamma rays.

Ag Cd + 113 113

47 48

0

-1

0

0

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Types of Natural Radioactive Emission

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Three major types of natural radioactive emission:

Beta particle (an electron from the nucleus)

Alpha particle( the nucleus of a He atom)

Gamma rays (energy similar to x-rays)

Copyright © Houghton Mifflin Company. All rights reserved. 11 | 13


Let’s look at Half-life

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The half-life of a radionuclide is the time required for ½ of it to decay.

Half-life is frequently given the symbol t1/2.



Half-life Decay Graph for 80 mg of Iodine-131

mf = mi

2n

1. mf is the f inal sample mass2. mi is the initial sample mass3. n is number of half -lives

Equation to Determine Final Mass of a Radionuclide

Practice Problem I :

How many grams of cobalt -60 is left when 2.0 g of it decays for 15.9 years? It t1/2 is 5.3 years.

Practice Problem II :

What is the t1/2 for the radionuclide potassium-45 ( a beta emitter) if a 50mg sample decays to 5.3 years.

Let’s look at the Biochemical Effects of Radiation


Nuclear Chemistry cont’dDegree of Penetration by BAG Radiation

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NPenuclear Chemistry cont’d

Alpha .. No damage to skin .. Why? ( greatest damage when ingested… Why?)

Beta ….. Severe burns to skin… Why?

Gamma….. Severe damage to skin and internal organs….. Why?


This is the last powerpoint slide in this chapter

This is the last powerpoint slide in this chapter

→ Fig. 11.4 Ernest Rutherford was the first person to carry out a bombardment reaction.



→ Table 11.2



CC 11.1 Tobacco RadioactivityNuclear Chemistry cont’d


→ Fig. 11.6 In the U-238 decay series, each nuclide is unstable except Pb-206.



← Fig. 11.7 Ion pair formation.



→ CC 11.2Irridated and nonradiated mushrooms


© Peticolas/Megna/Fundamental Photographs, NYC


← Fig. 11.9 Film badges are used to determine a person’s exposure to radiation.


Doug Plummer/Photo Researchers


Fig. 11.10 Radiation passing through a Geiger counter ionizes one or more gas atoms, producing ion pairs.



← Fig. 11.11 Components of the estimated annual radiation of an average American.



→ CC. 11.3A commercially available kit to test for radon gas in the home.



← Fig. 11.12 Brain scans are obtained using radioactive technetium-99, a laboratory-produced radionuclide.


Science Photo/Custom Medical Stock Photo


← Table 11.4



Table 11.5



→ Fig. 11.13 Cobalt-60 is used as a source of gamma radiation in radiation therapy.


Yoav Levy/Phototake


← Fig. 11.14 A fission chain reaction is caused by further reaction of the neutrons produced during fission.



→ Fig. 11.15 Enormous amounts of energy are released in the explosion of a nuclear fission bomb.


© Bettmann/CORBIS


← Fig. 11.16 The cooling tower at the Trojan nuclear power plant dominates the landscape. The nuclear reactor is housed in the dome-shaped enclosure.


© Albert J. Copley/Visuals Unlimited


→ Fig. 11.17 The process of nuclear fusion maintains the interior of the sun at the temperature of approximately 15 million degrees.


NASA



CAG 11.2


→ CO 11.1Associated with brain-scan technology is the use of small amounts of radioactive substances.


PhotoDisc

← Fig. 11.1 Marie Curie, one of the pioneers in the study of radioactivity, is the first person to have been awarded two Nobel Prizes for scientific work.



→ Table 11.6


Chapter 11 Nuclear Chemistry. 11 | 2 Nuclear Chemistry cont’d What is nuclear chemistry? The study of reactions that result from changes in the nucleus.

Documents

nuclear chemistry slide

radionuclide slide

halflife slide

chapter slide

atom slide

powerpoint slide

radioactive decay slide

bag radiation slide