chapter 24 nuclear chemistry (p. 858-899) i iv iii ii

CHAPTER 24

Nuclear Chemistry

CHAPTER 24

Nuclear Chemistry

(p. 858-899)(p. 858-899)I

IV

III

II

Section 24.1 Nuclear Radiation

Section 24.2 Radioactive Decay

Section 24.3 Nuclear Reactions

Section 24.4 Applications and Effects of Nuclear Reactions

Table Of ContentsCHAPTER24

CHAPTER 24

Nuclear Chemistry

CHAPTER 24

Nuclear ChemistryI. Nuclear I. Nuclear RadiationRadiationI. Nuclear I. Nuclear RadiationRadiation

I

IV

III

II

• Summarize the events that led to understanding radiation.

nucleus: the extremely small, positively charged, dense center of an atom that contains positively charged protons, neutral neutrons, and is surrounded by empty space through which one or more negatively charged electrons move

• Identify alpha, beta, and gamma radiations in terms of composition and key properties.

SECTION24.1

Nuclear Radiation

Student Learning essential questions-Section 1

• How was radioactivity discovered and studied?• What are the key properties of alpha, beta, and

gamma radiation?

Isotope

Radioisotope

X-ray

penetrating power

Under certain conditions, some nuclei can emit alpha, beta, or gamma radiation.

SECTION24.1

Nuclear Radiation

Warm -up

• List the three different types of radiation and their charges.

• Tell me the composition of the radiation type that can not penetrate paper because it is too large.

1. Alpha, +2; Beta, _1; Gamma, 0

2. Alpha, 2 protons and 2 neutrons

The Discovery of Radiation• Nuclear reactions are different from other types of

reactions.

• Nuclear chemistry is concerned with the structure of atomic nuclei and the changes they undergo.

• Marie Curie and her husband Pierre isolated the first radioactive materials.

SECTION24.1

Nuclear Radiation

The Discovery of Radiation (cont.)

SECTION24.1

Nuclear Radiation

Warm-Up

C. Johannesson

Isotopes

Isotopes …

Therefore, isotopes of the same element have different masses.

…of the same element have the same number of protons and electrons but different numbers of neutrons.

Isotopes ……don’t have to be radioactive.

Some isotopes are unstable and decay, releasing alpha or beta particles, or gamma rays.

But, there are many stable isotopes that don’t decay.

Isotopes …

Mass number - the sum of the protons and neutrons in the nucleus.

Atomic number - the number of protons in the nucleus of an atom.

…have different mass numbers but the same atomic number.

Symbols for Isotopes

EA

Z

Symbol of element

Mass number

Atomic number

A is the symbol for mass number

Z is the symbol for atomic number

U235

92


Symbol of Element

Mass number

Atomic number

An isotope of uranium


U235

92

Mass number

Symbol of Element

Atomic number An isotope of uranium

This form solves the word processor dilemma.

U-235

Symbol of Element

Mass numberHow do you know the atomic number?

Find U in the periodic table.


Z = 92

Some elements have several Isotopes

Lead has four naturally occurring isotopes, Pb-204, Pb-206, Pb-207, and Pb-208; but there are 23 man-made isotopes of lead.

Some elements have several Isotopes

Bismuth has only one naturally occurring isotope, Bi-209, but there are 22 man-made isotopes of bismuth.

How are isotopes of the same element alike and different?

Alike:1. Number of

protons and electrons

2. Atomic number3. Chemical

properties

Different:1. Number of

neutrons

2. Mass Number3. Atomic mass of

the isotopes

Types of Radiation

• Isotopes of atoms with unstable nuclei are called radioisotopes.

• Unstable nuclei emit radiation (release energy) to attain more stable atomic configurations in a process called radioactive decay.

• The three most common types of radiation are alpha, beta, and gamma.

SECTION24.1

Nuclear Radiation

Isotope- Atoms of the same element with different number of neutrons.

Types of Radiation (cont.)

SECTION24.1

Nuclear Radiation

He42

A. Types of Radiation

• Alpha particle ()– helium nucleus paper2+

Beta particle (-) electron e0

-11-

leadPositron (+)

positron e01

1+

Gamma () high-energy photon 0

concrete

• Alpha particles have the same composition as a helium nucleus—two protons and two neutrons.

• Because of the protons, alpha particles have a 2+ charge.

• Alpha radiation consists of a stream of particles.

SECTION24.1

Nuclear Radiation


• Alpha radiation is not very penetrating—a single sheet of paper will stop an alpha particle.

SECTION24.1

Nuclear Radiation


• Beta particles are very fast-moving electrons emitted when a neutron is converted to a proton.

• Beta particles have insignificant mass and a 1– charge.

SECTION24.1

Nuclear Radiation


• Beta radiation is a stream of fast moving particles with greater penetrating power—a thin sheet of foil will stop them.

SECTION24.1

Nuclear Radiation


• Gamma rays are high-energy electromagnetic radiation.

• Gamma rays have no mass or charge.

• Gamma rays almost always accompany alpha and beta radiation.

• X rays are a form of high-energy electromagnetic radiation emitted from certain materials in an excited state. (gamma rays)

SECTION24.1

Nuclear Radiation


• The ability of radiation to pass through matter is called its penetrating power.

• Gamma rays are highly penetrating because they have no charge and no mass.

SECTION24.1

Nuclear Radiation


Why do radioisotopes emit radiation?

A. to balance charges in the nucleus

B. to release energy

C. to attain more stable atomic configurations

D. to gain energy

SECTION24.1

Section Check

X rays are most similar to what type of nuclear emissions?

A. gamma rays

B. alpha particles

C. beta particles

D. delta waves

SECTION24.1

Section Check

CHAPTER 24

Nuclear Chemistry

CHAPTER 24

Nuclear Chemistry

II. Radio Active II. Radio Active DecayDecay

II. Radio Active II. Radio Active DecayDecay

I

IV

III

II

• Explain why certain nuclei are radioactive.

radioactivity: the process by which some substances spontaneously emit radiation• Apply your knowledge of

radioactive decay to write balanced nuclear equations.

• Solve problems involving radioactive decay rates.

SECTION24.2

Radioactive Decay


• Why are certain nuclei radioactive?• How can you use radioactive decay rates to analyze

samples of radioisotopes?

Transmutation

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

half-life

SECTION24.2

Radioactive Decay

Nuclear Stability

• Except for gamma radiation, radioactive decay involves transmutation, or the conversion of an element into another element.

• Protons and neutrons are referred to as nucleons.

• All nucleons remain in the dense nucleus because of the strong nuclear force.

SECTION24.2

Radioactive Decay

B. Nuclear Decay

• Alpha Emission

He Th U 42

23490

23892

parentnuclide

daughternuclide

alphaparticle

Numbers must balance!!

B. Nuclear Decay

• Beta Emission

e Xe I 0-1

13154

13153

electronPositron Emission

e Ar K 01

3818

3819

positron

B. Nuclear Decay

• Electron Capture

Pd e Ag 10646

0-1

10647

electronGamma Emission

Usually follows other types of decay.

Transmutation One element becomes another.

Types of Radioactive Decay

• Atoms can undergo different types of decay—beta decay, alpha decay, positron emission, or electron captures—to gain stability.

SECTION24.2

Radioactive Decay

Types of Radioactive Decay (cont.)

• In beta decay, radioisotopes above the band of stability have too many neutrons to be stable.

• Beta decay decreases the number of neutrons in the nucleus by converting one to a proton and emitting a beta particle.

SECTION24.2

Radioactive Decay

• In alpha decay, nuclei with more than 82 protons are radioactive and decay spontaneously.

• Both neutrons and protons must be reduced.

• Emitting alpha particles reduces both neutrons and protons.

SECTION24.2

Radioactive Decay


SECTION24.2

Radioactive Decay


• Nuclei with low neutron to proton ratios have two common decay processes.

• A positron is a particle with the same mass as an electron but opposite charge.

• Positron emission is a radioactive decay process that involves the emission of a positron from the nucleus.

SECTION24.2

Radioactive Decay


• During positron emission, a proton in the nucleus is converted to a neutron and a positron, and the positron is then emitted.

• Electron capture occurs when the nucleus of an atom draws in a surrounding electron and combines with a proton to form a neutron.

SECTION24.2

Radioactive Decay


SECTION24.2

Radioactive Decay


B. Nuclear Decay• Why nuclides decay…

– need stable ratio of neutrons to protons

He Th U 42

23490

23892

e Xe I 0-1

13154

13153

e Ar K 01

3818

3819

Pd e Ag 10646

0-1

10647

DECAY SERIES TRANSPARENCY

C. Half-life

• Half-life (t½)– Time required for half the atoms of a radioactive

nuclide to decay.– Shorter half-life = less stable.

C. Half-life

nif mm )( 2

1

mf: final massmi: initial massn: # of half-lives

C. Half-life/Warm-Up

C. Johannesson

Fluorine-21 has a half-life of 5.0 seconds. If you start with 25 g of fluorine-21, how many grams would remain after 60.0 s?

n = (t) ÷ (T); t = total elapsed time, T = length of half life.

GIVEN:

T½ = 5.0 s

mi = 25 g

mf = ?

t = 60.0 s

n = 60.0s ÷ 5.0s =12

WORK:

mf = mi (½)n

mf = (25 g)(0.5)12

mf = 0.0061 g

C. Half-life

C. Johannesson

The half-life of radium-224 is 3.66 days. What was the original mass of radium-224 if 0.0500 grams remains after 7.32 days? Show all work!

GIVEN:T½ = 3.66 days

mi = ?

mf = 0.0500

Elapsed time (t) = 7.32 days

n = 7.32 days ÷ 3.66 days = 2.00

WORK:

mf = mi (½)n

mf = (mi)(0.5)2

mf = 0.0500 g

.0500 g = (mi)(0.5)2

mi = 0.0500 g ÷ 0.25 = 0.2 g

C. Half-life

C. Johannesson

Exactly 1/16th of a given amount of protactinum-234 remains after 26.75 hours. What is the half-life of protactinum-234? Show all work!

GIVEN:Lets say original amount (mi) = 100g proctactinum-234.100 g X (1/16) -= 6.25 g

50 g = 1st half-life

25 g = 2nd half-life

12.5 g = 3rd half-life

6.25 g = 4th half-life

WORK:

mf = mi (½)n

n = 4- half lives

T = 26.75 ÷ 4 = 6.69 hours

Radioactive Decay Rates (cont.)

SECTION24.2

Radioactive Decay

SECTION24.2

Radioactive Decay


• The process of determining the age of an object by measuring the amount of certain isotopes is called radiochemical dating.

• Carbon-dating is used to measure the age of artifacts that were once part of a living organism.

SECTION24.2

Radioactive Decay


The process of converting one element into another by radioactive decay is called ____.

A. half-life

B. nuclear conversion

C. transmutation

D. trans-decay

SECTION24.2

Section Check

An unknown element has a half-life of 40 years. How much of a 20.0g sample will be left after 120 years?

A. 0.00g

B. 2.50g

C. 5.00g

D. 7.50g

SECTION24.2

Section Check

CHAPTER 24

Nuclear Chemistry

CHAPTER 24

Nuclear ChemistryIII. Nuclear III. Nuclear ReactionsReactionsIII. Nuclear III. Nuclear ReactionsReactions

I

IV

III

II

• Understand that mass and energy are related.

mass number: the number after an element’s name, representing the sum of its protons and neutrons• Compare and contrast

nuclear fission and nuclear fusion.

• Explain the process by which nuclear reactors generate electricity.

SECTION24.3

Nuclear Reactions


• How are nuclear equations balanced?• How are mass and energy related?• How do nuclear fission and nuclear fusion compare

and contrast?• What is the process by which nuclear reactors

generate electricity?

nuclear fission

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

nuclear fusion

SECTION24.3

Nuclear Reactions

Induced Transmutation

• One element can be converted into another by spontaneous emission of radiation.

• Elements can also be forced to transmutate by bombarding them with high-energy alpha, beta, or gamma radiation.

SECTION24.3

Nuclear Reactions

Warm-Up: Writing Nuclear Equations

• Write a balanced equation for the alpha decay of thorium-232. Turn to Pg. 868, Table 3, and page 869 in Text book, to help getting started.

Answer:

Warm-Up:Balancing a Nuclear reaction

• NASA uses the alpha decay of plutonium-238, as a heat source on spacecraft. Write a balanced

equation for this decay.

Analyze this problem- You are given that a plutonium atom undergoes alpha decay and forms an unknown product. Plutonium-238 is the initial reactant, while the alpha particle is one of the products of the reaction. The reaction is summarized in the equation below.

Determine the unknown product of the reaction, X

Writing and Balancing Nuclear Equations

• Nuclear reactions are expressed by balanced nuclear equations.

• In balanced nuclear equations, mass numbers and charges are conserved.

–Ex. A plutonium-238 atom undergoes alpha decay, write a balanced equation for this decay.

SECTION24.2

Radioactive Decay

SECTION24.2

Radioactive Decay

Writing and Balancing Nuclear Equations

Induced Transmutation (cont.)

• The process of striking nuclei with high-velocity charged particles is called induced transmutation.

SECTION24.3

Nuclear Reactions

• Particle accelerators use electrostatic and magnetic fields to accelerate charged particles to very high speed.

• Transuranium elements are the elements with atomic numbers 93 and higher, immediately following uranium.

SECTION24.3

Nuclear Reactions

Induced Transmutation (cont.)

Nuclear Reactions and Energy

• Mass and energy are related.

• Loss or gain in mass accompanies any reaction that produces or consumes energy.

SECTION24.3

Nuclear Reactions

Nuclear Reactions and Energy (cont.)

• Most chemical reactions produce or consume so little energy that the accompanying changes in mass are negligible.

• Energy released from nuclear reactions have significant mass changes.

SECTION24.3

Nuclear Reactions

• The mass of a nucleus is always less than the sum of the masses of the individual protons and neutrons that comprise it.

• The difference between a nucleus and its component nucleons is called the mass defect.

• Binding together or breaking an atom’s nucleons involves energy changes.

SECTION24.3

Nuclear Reactions


• Nuclear binding energy is the amount of energy needed to break 1 mol of nuclei into individual nucleons.

SECTION24.3

Nuclear Reactions


Nuclear Fission

• The splitting of nuclei into fragments is known as nuclear fission.

• Fission is accompanied with a very large release of energy.

SECTION24.3

Nuclear Reactions

Nuclear Fission (cont.)

• Nuclear power plants use fission to produce electricity by striking uranium-235 with neutrons.

SECTION24.3

Nuclear Reactions


• Each fission of U-235 releases two additional neutrons.

• Each of those neutrons can release two more neutrons.

• The self-sustaining process is called a chain reaction.

SECTION24.3

Nuclear Reactions

SECTION24.3

Nuclear Reactions


• Without sufficient mass, neutrons escape from the sample before starting a chain reaction.

• Samples with enough mass to sustain a chain reaction are said to have critical mass.

SECTION24.3

Nuclear Reactions


SECTION24.3

Nuclear Reactions


U-235

U-235

U-235

Nuclear fission

Neutron

Neutrons

Fission fragment

Fission fragment

Nuclear fission

U-235

U-235

Neutrons

Fission fragment

These U-235 atoms can split when hit by neutrons, and release

more neutrons, starting a chain

reaction.

Nuclear fission

To picture a chain reaction, imagine 50 mousetraps in a wire cage.

And on each mousetrap are two ping-pong balls.

Now imagine dropping one more ping-pong ball into the cage …

Detail of ping-pong balls on mousetraps.

http://www.physics.montana.edu/demonstrations/video/modern/demos/mousetrapchainreaction.html

http://www.physics.montana.edu/demonstrations/video/modern/demos/mousetrapchainreaction.html

Nuclear fission

Billions of splitting atoms releases a huge amount of heat energy.

This energy originally held the nucleus together.

As the chain reaction proceeds, energy is released as heat energy.

Nuclear fission

This heat energy can be harnessed to boil water,

creating steam,

that can spin a turbine,

that can turn a generator,

creating electricity.

Nuclear Fusion

• It is possible to bind together two or more lighter elements (mass number less than 60).

• The combining of atomic nuclei is called nuclear fusion.

• Nuclear fusion is capable of releasing very large amounts of energy.

SECTION24.3

Nuclear Reactions

Nuclear Fusion (cont.)

• Fusion has several advantages over fission.

− Lightweight isotopes are abundant.

− Fusion products are not radioactive.

− However, fusion requires extremely high energies to initiate and sustain a reaction.

SECTION24.3

Nuclear Reactions

• Fusion reactions are also known as thermonuclear reactions.

• Many problems must be solved before nuclear fusion is a practical energy source.

SECTION24.3

Nuclear Reactions

Nuclear Fusion (cont.)

Nuclear Reactors

• Nuclear fission produces the energy generated by nuclear reactors.

• The fission within a reactor is started by a neutron-emitting source and is stopped by positioning the control rods to absorb virtually all of the neutrons produced in the reaction.

SECTION24.3

Nuclear Reactions

Nuclear Reactors (cont.)

• The reactor core contains a reflector that reflects neutrons back into the core, where they react with fuel rods.

• Nuclear reactors produce highly radioactive nuclear waste.

• Breeder reactors produce more fuel than they consume.

SECTION24.3

Nuclear Reactions

SECTION24.3

Nuclear Reactions

Nuclear Reactors (cont.)

Bombarding a nuclei with charged particle in order to create new elements is called ____.

A. nuclear conversion

B. nuclear decay

C. induced decay

D. induced transmutation

SECTION24.3

Section Check

Thermonuclear reactions involve:

A. splitting nuclei into smaller fragments

B. fusing nuclei together to form larger particles

C. bombarding nuclei with charged particles

D. generating electricity in a nuclear reactor

Section CheckSECTION24.3

CHAPTER 24

Nuclear Chemistry

CHAPTER 24

Nuclear Chemistry

IV- IV- Applications and Effects of Nuclear Reactions

IV- IV- Applications and Effects of Nuclear Reactions

I

IV

III

II

• Describe several methods used to detect and measure radiation.

isotope: an atom of the same element with the same number of protons but different number of neutrons

• Explain an application of radiation used in the treatment of disease.

• Describe some of the damaging effects of radiation on biological systems.

SECTION24.4

Applications and Effects of Nuclear Reactions


• What are several methods used to detect and measure radiation?

• How is radiation used in the treatment of disease?• What are some of the damaging affects of radiation

on biological systems?

ionizing radiation

radiotracer

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

SECTION24.4


Detecting Radioactivity• Radiation with enough energy to ionize matter it

collides with is called ionizing radiation.

• The Geiger counter uses ionizing radiation to detect radiation.

SECTION24.4


Detecting Radioactivity (cont.)

• A scintillation counter detects bright flashes when ionizing radiation excites electrons of certain types of atoms.

SECTION24.4


Uses of Radiation

• When used safely, radiation can be very useful.

• A radiotracer is a radioactive isotope that emits non-ionizing radiation and is used to signal the presence of an element or specific substrate.

SECTION24.4


Uses of Radiation (cont.)

• Radiation can damage or destroy healthy cells.

• Radiation can also destroy unhealthy cells, such as cancer cells.

• Unfortunately, radiation therapy also destroys healthy cells in the process of destroying cancerous cells.

SECTION24.4


Biological Effects of Radiation

• Radiation can be very harmful.

• The damage depends on type of radiation, type of tissue, penetrating power, and distance from the source.

SECTION24.4


Biological Effects of Radiation (cont.)

• High energy radiation is dangerous because it produces free radicals.

• Free radicals are atoms or molecules that contain one or more unpaired electrons.

• Free radicals are highly reactive.

SECTION24.4


• Two units measure doses of radiation.

• The rad stands for Radiation-Absorbed Dose, which is the amount of radiation that results in 0.01 J of energy per kilogram of tissue.

• The rad does not account for the type of tissue that is absorbing the radiation.

• The rad is multiplied by a factor related to its effect on the tissue involved and is called the rem, Roentgen Equivalent for Man.

SECTION24.4



SECTION24.4



• I1d12 = I2d2

2 where I = intensity and d = distance.

SECTION24.4



Nuclear reactor

Nuclear reactor

Reactor core

Containment building

Fue

l rod

s

Heat exchangerSteam generator

Water circulates in the core

Steam to turbine

Water from cooling lake


Nuclear reactor

Reactor core


Fue

l rod

s


Steam to turbine

Cadmium control rods – absorb neutrons


Nuclear reactor

Reactor core

Fue

l rod

s


Steam to turbine

The water in the core serves two functions.

(1) The water cools the core and carries away heat. (2) Water is a moderator. The water slows the neutrons so

that they can cause fission. Fast neutrons do not cause fission.


Nuclear reactor

Reactor core


Fue

l rod

s



Nuclear reactor

Reactor core


Fue

l rod

s



Steam to turbine


From nuclear energy to…

Steam to turbine

Water from cooling lake Cooling towers or

lake

turbine generator

Transmission wires

Condensed steam


Steam to turbine


lake

turbine generator

Transmission wires

Condensed steam


Electrical energy

Steam to turbine


lake

turbine generator

Transmission wires

Condensed steam


Electrical energy

This part of the system is the same regardless of how the steam is produced. The heat can come from nuclear energy or by burning coal, natural gas or fuel oil.

Electrical energy

In fact, the only purpose of a nuclear reactor is to boil water.

Pros and cons

Cheap, plentiful power, no CO2, nuclear waste, terrorist attack, running out of oil and coal, on-site storage, breeder reactors, transportation of spent fuel, “not in my backyard”, …

What is a radioisotope that emits non-ionizing radiation and is used to signal the presence of certain elements called?

A. rad

B. rem

C. radiotracer

D. free radical

SECTION24.4

Section Check

Radiation with enough energy to cause tissue damage by ionizing the particles it collides with is called ____.

A. alpha decay

B. beta decay

C. gamma radiation

D. ionizing radiation

SECTION24.4

Section Check

Key Concepts

• Wilhelm Roentgen discovered X rays in 1895.

• Henri Becquerel, Marie Curie, and Pierre Curie pioneered the fields of radioactivity and nuclear chemistry.

• Radioisotopes emit radiation to attain more-stable atomic configurations.

Study Guide

SECTION24.1

Nuclear Radiation

Key Concepts• The conversion of an atom of one element to an atom of another by

radioactive decay processes is called transmutation.

• Atomic number and mass number are conserved in nuclear reactions.

• A half-life is the time required for half of the atoms in a radioactive sample to decay.

• Radiochemical dating is a technique for determining the age of an object by measuring the amount of certain radioisotopes remaining in the object.

SECTION24.2

Radioactive Decay

Study Guide

Key Concepts

• Induced transmutation is the bombardment of nuclei with particles in order to create new elements.

• In a chain reaction, one reaction induces others to occur. A sufficient mass of fissionable material is necessary to initiate the chain reaction.

• Fission and fusion reactions release large amounts of energy.

E = mc2

SECTION24.3

Nuclear Reactions

Study Guide

Key Concepts

• Different types of counters are used to detect and measure radiation.

• Radiotracers are used to diagnose disease and to analyze chemical reactions.

• Short-term and long-term radiation exposure can cause damage to living cells.

SECTION24.4


Study Guide

The half-life of a radioisotope is:

A. one-half its total life

B. 2500 years

C. the amount of time it takes to completely decay

D. the amount of time it takes for one-half to decay

Chapter Assessment

Nuclear ChemistryCHAPTER24

What is a positron?

A. a nucleon with the same mass as a neutron and a positive charge

B. a nucleon with the same mass as a proton and a negative charge

C. a nucleon with the same mass as an electron and a positive charge

D. a type of radioactive emission with a negative charge


Chapter Assessment

What is the force that holds the protons and neutrons together in the nucleus of an atom?

A. nuclear magnetic force

B. strong nuclear force

C. ionic bonding

D. nuclear bond


Chapter Assessment

During positron emission, a proton is converted to:

A. a neutron and electron

B. an electron and positron

C. a proton and neutron

D. a neutron and positron

Chapter Assessment


A thermonuclear reaction is also called ____.

A. nuclear fission

B. nuclear fusion

C. mass defect

D. critical mass


Chapter Assessment

Which statement is NOT true of beta particles?

A. They have the same mass as an electron.

B. They have a charge of 1+.

C. They are less penetrating than alpha particles.

D. They are represented by 0-1β.

Standardized Test Practice


The site that oxidation occurs at in a battery is called ____.

A. anode

B. cathode

C. nothode

D. salt bridge



A solution of 0.500M HCl is used to titrate 15.00mL if KOH solution. The end point of the titration is reached after 25.00 mL of HCl is added. What is the concentration of KOH?

A. 9.00M

B. 1.09M

C. 0.833M

D. 0.015M



The half-life of K-40 is 1.26 × 109 years. How much of a 10.0g sample will be left after 200 million years?

A. 8.96g

B. 8.03g

C. 7.75g

D. 4.99g



Elements above the band of stability are radioactive and decay by ____.

A. alpha decay

B. beta decay

C. positron emission

D. electron capture



Nuclear Properties TableProperty Alpha Beta Gamma

Greek Letter

Symbol

Actually is…

Atomic number

Mass number

Relative mass

Relative charge

Penetrating

Shielding

Stop!Complete the chart on notebook paper, then continue.


Greek Letter

Symbol

Actually is…

Atomic number

Mass number

Relative mass

Relative charge

Penetrating

Shielding


Greek Letter Symbol

Actually is…

Atomic number

Mass number

Relative mass

Relative charge

Penetrating

Shielding


Greek Letter Symbol

2He4-1e0 NA

Actually is…

Atomic number

Mass number

Relative mass

Relative charge

Penetrating

Shielding


Greek Letter Symbol

2He4-1e0 NA

Actually is… He nucleus electron EM energy

Atomic number

Mass number

Relative mass

Relative charge

Penetrating

Shielding


Greek Letter Symbol

2He4-1e0 NA


Atomic number 2 -1 NA

Mass number

Relative mass

Relative charge

Penetrating

Shielding


Greek Letter Symbol

2He4-1e0 NA



Mass number 4 0 NA

Relative mass

Relative charge

Penetrating

Shielding


Greek Letter Symbol

2He4-1e0 NA



Mass number 4 0 NA

Relative mass 4 1/1837NA

Relative charge

Penetrating

Shielding


Greek Letter Symbol

2He4-1e0 NA



Mass number 4 0 NA


Relative charge +2 -1 NA

Penetrating

Shielding


Greek Letter Symbol

2He4-1e0 NA



Mass number 4 0 NA



Penetrating Low Medium High

Shielding


Greek Letter Symbol

2He4-1e0 NA



Mass number 4 0 NA



Penetrating Low Medium High

Shielding 2.5 cm of air;anything else

Metal, plastic or wood

Lead or concrete

chapter 24 nuclear chemistry (p. 858-899) i iv iii ii

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