Nuclear Chemistry

Nuclear Chemistry Objectives• Students will be able to identify what radioisotopes

are and why they undergo radioactivity.• Students will be able to compare properties of

nuclear reactions with chemical reactions.• Students will demonstrate understanding of

radioactive decay through application and graphing. • Students will assess the application of nuclear

chemistry as a continual alternative resource of energy for developed countries.

• Students will understand and classify nuclear reactions by the types of radiation produced.

Nuclear Reactions vs. Chemical Reactions

Chemical Reactions Nuclear Reactions

Similarities

Radioisotopes • Radioisotopes = Atoms with unstable nuclei.

• Why are some atoms’ nuclei unstable?(Use nuclear stability graph to answer this question)

Nuclear Band of Stability

http://www.hasdeu.bz.edu.ro/softuri/fizica/mariana/Atomica/Table/lessons/11nuclear/nuclear.htm

Radioisotopes • Radioisotopes = Atoms with unstable nuclei.

• Unstable nucleus = disproportional ratio of protons to neutrons to stabilize nucleus.

Nuclear Band of Stability

http://www.hasdeu.bz.edu.ro/softuri/fizica/mariana/Atomica/Table/lessons/11nuclear/nuclear.htm

*Big Misconception: Stable nucleus means equal number of protons and neutrons. From graph, students confirmed that most elements with a stable nucleus needs more neutrons to minimize the repulsion force between protons with a similar charge.

Radioisotopes • Radioisotopes = Atoms with unstable nuclei.

• Unstable nucleus = disproportional ratio of protons to neutrons to stabilize nucleus.

• Most elements with atomic #s < 83 have at least one radioisotope.

• All elements with atomic #s > 83 are radioisotopes.

Radiosotope’s Notation• What is the radioisotope notation for each of the

following? a. Polonium (Po). It has a mass number of 210.

b. Plutonium (Pu). It has a mass number of 245.

c. Rn-240 with an atomic number of 86.

d. Th-230.

Nuclear Reactions: Bell Ringer1. Identify a similarity and a difference between chemical

and nuclear reactions?

2. What is a radioisotope?

3. Using the Nuclear Band of Stability graph to determine which of the following elements are radioisotopes.

a. C -12 b. C-14 c. U-238 d. Nd-140

Nuclear Band of Stability

http://www.hasdeu.bz.edu.ro/softuri/fizica/mariana/Atomica/Table/lessons/11nuclear/nuclear.htm

• Reactions that occur within the nucleus of radioisotopes in order to stabilize it.

• Also called: radioactive decay; radioactivity

• Spontaneous reactions (occurs naturally).

• Reaction rates remain constant for radioisotopes despite changes in temperature, pressure, or addition of a catalyst.

Nuclear Reactions

Nuclear Equations

parent decays α + daughter isotopeisotope particle (stable) (unstable)

•Illustrate the nuclear process in which radioisotopes become stable.

Infinite Campus Update:

• “Radioactivity” article questions: (10pts)

• Due Mon., March 19th: Graphing Skills Wksht (10pts.) Radioactive Decay Lab (15pts.)

Due Tues., March 20th: Formal Lab Report draft (15pts.)

• Reactions that occur within the nucleus of radioisotopes in order to stabilize it.

• Also called: radioactive decay; radioactivity

• Spontaneous reactions (occurs naturally).

• Reaction rates remain constant for radioisotopes despite changes in temperature, pressure, or addition of a catalyst.

Nuclear Reactions

Nuclear Equations

parent decays α + daughter isotopeisotope particle (stable) (unstable)

•Illustrate the nuclear process in which radioisotopes become stable.

•Half-Life: The time it takes for half of the radioisotope sample (parent isotopes) to decay into a more stable isotope (daughter isotope)

Graphing Skills Worksheet # of Half-Lives Parent

Isotope(grams)

Daughter Isotope(grams)

# of Half-Lives Parent Isotope(grams)

Daughter Isotope(grams)

0 3

1 4

2 5

Radioactive Decay LabPurpose: Simulate and graph the radioactive decay

of an artificial radioisotope, M&Mium. Revised Procedures:

Pre-Lab Questions: 1. What side of the candy represents the parent isotope?2. What side of the candy represent the daughter isotope?3. What is the half-life of the M&Mium radioisotope?

Hypothesis: Complete on lab.

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usd314.k12.ks.us

Radioactive Decay Lab: Revised Procedures1. Carefully pour the M&Mium radioisotope sample onto a plate.2. Count the number of M&Mium radioisotopes in sample and record in table

under 0 half-life.3. Cover sample with another plate and gently shake for 10 seconds. Record time

in table under first half-life. 4. Remove the top plate and count the number of M&Miums that have decayed

into the daughter isotope(candy with no M&M print) during the first half-life. Record in table.

5. Consume the daughter isotopes (decayed isotopes). 6. Count the remaining M&Mium radioisotopes after the first half-life and record

in table. 7. Continue shaking for 10 seconds, counting, recording, and consuming until all

the M&Mium sample has decayed into the more stable daughter isotope. 8. Graph the rate of decay for the M&Mium radioisotope and the rate of

production for the daughter isotope. • Independent variable: half-life time (seconds)• Dependent variable: number of isotopes

Radioactive Decay Lab: Data Table Number of Half-Lives

Total Time(seconds)

# of M&Miums(parent isotope)

Daughter Isotope(decayed)

0

1

2

3

4

5

6

7

Nuclear Radiation• Nuclear Radiation= matter and large amounts

of energy produced during a nuclear reaction.• Three types of nuclear radiation1.Alpha radiation (α )2.Beta radiation (β)3.Gamma radiation (ϒ)

Types of Nuclear Radiation•Types of radiation can be classified by their charges.

Nuclear Radiation

paper

wood

concrete or lead

Types of radiation can be classified by type of shielding.

(alpha particle)

(beta particle)

(gamma particle)

Nuclear Energy

www.nukepills.com

Bell Ringer: Nuclear Chemistry

1. What is a radioisotope and give an example of an element that has or is one?

2. Write the radioisotope notation for radon which has a mass # of 221?

3. Identify a similarity and difference between chemical and nuclear reactions?

Nuclear Chemistry Objectives• Students will be able to identify what radioisotopes

are and why they undergo radioactivity.

• Students will be able to compare properties of nuclear reactions with chemical reactions.

• Students will demonstrate understanding of radioactive decay through application and graphing.

• Students will assess the application of nuclear chemistry as a continual alternative resource of energy for developed countries.

Nuclear Energy

www.nukepills.com

Radioactive Decay DataM&Mium

Half-Life Total Time (sec.) (x-axis)

M&Miumparent isotope(Unstable)

Daughter Isotope(stable)

0 0 200 0

1 10

2 20

3 30

4 40

5 50

6 60

7 70

Kandium Radioactive Lab

1. a.How much of the daughter isotope is present at 38 seconds?

b. How much of the parent isotope is present at 38 seconds?

Nuclear Chemistry:Homework Problems

Nuclear Chemistry Objectives• Students will understand and classify nuclear

reactions by the types of radiation produced.

Nuclear Radiation• Types of radiation can be classified by changes in

mass number and atomic number between the parent isotope and the daughter isotope.

Alpha (α ) Radiation

parent decays α + daughter isotopeisotope particle (stable) (unstable) (He nucleus)

• change in mass number:

• change in atomic number:

Transmutation

parent decays α + daughter isotopeisotope particle (stable) (unstable) (He nucleus)

Transmutation: •An element is converted to a new element during radioactive decay.•A parent isotope is converted to daughter isotope•An unstable atom converted to a more stable atom.•Atomic number changes during radioactive decay

Alpha (α) Radiation• α symbol

• α charge?

• α shielding?

• Does transmutation occur when α radiation is emitted during radioactive decay?

Beta (β) Radiation

β particle • change in mass number:

• change in atomic number:

Beta (β) Radiation

• β symbol?

• β charge?

• β shielding?

• Does a transmutation occur when β radiation is emitted during radioactive decay?

Gamma (ϒ) Radiation

parent decays α + daughter isotope + ϒ

isotope particle (stable) (unstable) (He nucleus)

+ϒ

• change in mass number:

• change in atomic Number:

Gamma(ϒ) Radiation: • ϒ symbol?

• ϒ charge?

• ϒ shielding?

• Does it cause transmutation when ϒ radiation is emitted during radioactive decay?

Bell Ringer1. Identify which isotope is least stable?

a. F, F b. Al , Al

2. What is the nuclear equation for the alpha decay of the following radioisotope? U-235

3. If the products of a nuclear reaction are Xe-131 and a β particle what would the equation be?

Nuclear Chemistry Objective

• Students can explain the difference between fission and fusion.

• Students can analyze the benefits and risks of nuclear energy

Transmutation

Transmutation occurs during:1. Radioactive Decay

2. Bombarding an atom’s nucleus with particles.-can occur naturally or artificially-can cause or change the rate of a nuclear

reaction.

Fission vs. FusionFission Fusion

Similarities

Nuclear Fission• Fission is the splitting of a heavy nucleus by

bombarding it with neutrons.

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Nuclear Fission Application

chm.bris.ac.ukenglish-online.at

•Generates electricity where only steam is released into the environment.

Nuclear Fission Problem

• Nuclear Waste: Spent fuel rods must be disposed of properly. (pg. 812 in text)

• On-site or off-site holding tanks called pools.

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Nuclear Fusion• Nuclear Fusion – Small radioisotope nuclei

combine.

mrbarlow.wordpress.commrbarlow.wordpress.com

Nuclear Fusion

• Produces immense amount of energy.

• Does not produce nuclear waste• Applications? Not yet. Requires immense amount of energy.

Example: sun (40,000,000 0C)

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