Nuclear ChemistryNuclear Chemistry

Parts of the atomParts of the atom

ParticleParticle ChargeCharge Mass (g)Mass (g) Mass (amu)Mass (amu)

ProtonProton +1+1 1.672 x 101.672 x 10-24-24 11

NeutronNeutron 00 1.675 x 101.675 x 10-24-24 11

ElectronElectron -1-1 9.110x109.110x10-28-28 1/18391/1839

Parts of the atomParts of the atom

Nuclear chemistryNuclear chemistry

Most chemical changes deals with the electronMost chemical changes deals with the electron Nuclear chemistry deals with changes in the Nuclear chemistry deals with changes in the

nucleus, often accompanied by a release of a nucleus, often accompanied by a release of a large amount of energylarge amount of energy

RadiationRadiation Radiation is energy in transit in the form of high Radiation is energy in transit in the form of high

speed particles and electromagnetic waves speed particles and electromagnetic waves Radiation cannot be tasted, felt, or smelt, but has the Radiation cannot be tasted, felt, or smelt, but has the

potential to do a great deal of damagepotential to do a great deal of damage There are 4 particles or waves of radiation we will There are 4 particles or waves of radiation we will

learn aboutlearn about Alpha Alpha BetaBeta GammaGamma NeutronNeutron

Alpha particleAlpha particle

Symbol: Symbol: 2244He or He or

It is composed of 2 protons, 2 neutrons, has a It is composed of 2 protons, 2 neutrons, has a mass of 4 amus and a charge of 2mass of 4 amus and a charge of 2++

Low energyLow energy

Beta particleBeta particle

Symbol: Symbol: -1-100e or e or

A high energy electronA high energy electron Charge -1Charge -1

Gamma raysGamma rays

Gamma rays unlike the Gamma rays unlike the or or particle is not a particle is not a particle, instead a ray similar to an x-rayparticle, instead a ray similar to an x-ray

Symbol: Symbol: It is a ray it has no mass or chargeIt is a ray it has no mass or charge Very high energyVery high energy

NeutronNeutron

Symbol:Symbol:0011nn

It has a mass of one, no protons, and no chargeIt has a mass of one, no protons, and no charge

Types of nuclear radiationTypes of nuclear radiation

RadiationRadiationType ofType ofRadiationRadiation

Mass Mass (AMU)(AMU)

ChargeCharge Shielding materialShielding material

AlphaAlpha ParticleParticle 44 22 Paper, skin, clothesPaper, skin, clothes

BetaBetaParticleParticle 1/18361/1836 ±1±1

Plastic, glass, light Plastic, glass, light metalsmetals

GammaGamma ElectromagElectromag-netic Wave-netic Wave 00 00

Dense metal, Dense metal, concrete, Earthconcrete, Earth

NeutronsNeutrons ParticleParticle 11 00 Water, concreteWater, concrete

From: http://www.physics.isu.edu/radinf/properties.htm

Review: Atomic number and mass Review: Atomic number and mass numbernumber

Atomic number = Atomic number = number of protons = number of protons = symbol.symbol.

Atoms are electronically Atoms are electronically neutral. neutral. Number of electrons = Number of electrons =

number of protonsnumber of protons Mass number = # Mass number = #

protons + # neutronsprotons + # neutrons

ElementElement ProtonsProtons ElectronElectron NeutronsNeutrons

HH         

OO         

SS         

ClCl         

RnRn         

A +/-q

ZX

X=symbolZ=atomic number (# of protons)A=mass number (# of protons + # neutrons)q= charge (+=electrons<protons, -=electrons>protons)

Atomic number and mass numberAtomic number and mass number

How would we write H in this form?

IsotopesIsotopes IsotopesIsotopes

IsotopesIsotopes Isotopes-atoms of the same element (same Isotopes-atoms of the same element (same

number of protons) that have different number number of protons) that have different number of neutronsof neutrons

24

12Mg

25

12Mg

26

12Mg

Radioactive decay (natural) Radioactive decay (natural) Radioactive decay-when a nucleus breaks Radioactive decay-when a nucleus breaks

down by emitting radiation (naturally down by emitting radiation (naturally occurring)occurring)

92238

U → 90234Th + Which of the radioactive

particles?

Radioactive nucleus

New nucleus

radiation

(, , or )→ +

Radioactive decay-when a nucleus breaks Radioactive decay-when a nucleus breaks down by emitting radiation (naturally down by emitting radiation (naturally occurring)occurring)

Radioactive nucleus

New nucleus

radiation

(, , or )→ +

92238

U → 90234Th + 2

4He

Radioactive decay (natural) Radioactive decay (natural)

Radioactive decay (natural)Radioactive decay (natural)

Radioactive decay Radioactive decay and and : practice: practice

9595

241241Am Am → ? + → ? + 2244HeHe

? → ? → 771414N + N + -1-1

00ee

? → ? → 16163232S + S + -1-1

00ee

2727

6060Co → Co → 28286060Ni +?Ni +?

8888

226226Ra Ra → → 8686222222Rn + ?Rn + ?

? → ? → 8484218218Po + Po + 22

44HeHe

2626

5959Fe → Fe → 27275959Co + ?Co + ?

Radioactive decay Radioactive decay and and : practice: practice

9595

241241Am Am → → 9393237237Np + Np + 22

44HeHe

661414C → C → 77

1414N + N + -1-100ee

1515

3232P → P → 16163232S + S + -1-1

00ee

2727

6060Co → Co → 28286060Ni + Ni + -1-1

00ee

8888

226226Ra Ra → → 8686222222Rn + Rn + 22

44He He

8686

222222Rn → Rn → 8484218218Po + Po + 22

44HeHe

2626

5959Fe → Fe → 27275959Co + Co + -1-1

00ee

Gamma decayGamma decay

There are very few pure gamma emitters, There are very few pure gamma emitters, although gamma radiation accompanies most although gamma radiation accompanies most and and decay decay

In radiology one of the most commonly used In radiology one of the most commonly used gamma emitters is Tcgamma emitters is Tc

4343

99m99mTc Tc →→43439999Tc + Tc +

A gamma decay will have no change in the A gamma decay will have no change in the atomic number or atomic massatomic number or atomic mass

Bombardment ReactionBombardment Reaction

Bombardment reaction-bombarding 2 stable atoms Bombardment reaction-bombarding 2 stable atoms together, creating a radioisotopetogether, creating a radioisotope

All of the known elements whose atomic number is All of the known elements whose atomic number is greater than 92 were created from bombardment greater than 92 were created from bombardment reactionsreactions

Bombardment reactions: practiceBombardment reactions: practice

9898

249249Cf + ? Cf + ? → → 105105263263Db + Db + 00

11nn

2828

5858Ni +Ni + 1 111H → ? + H → ? + 22

44HeHe

2727

5959Co + ? → Co + ? → 25255656Mn +Mn +22

44HeHe

771414N + N + 22

44He → He → 881717O + ? O + ?

Bombardment reactions: practiceBombardment reactions: practice

9898

249249Cf + Cf + 771515N N → → 105105

263263Db + Db + 0011nn

2828

5858Ni +Ni + 1 111H → H → 2727

5555Co + Co + 2244HeHe

2727

5959Co + Co + 0011n → n → 2525

5656Mn +Mn +2244HeHe

771414N + N + 22

44He → He → 881717O + O + 11

11HH