Nuclear ChemistryNuclear Chemistry

Nuclear reactions involve unstable Nuclear reactions involve unstable nuclei becoming more stable by nuclei becoming more stable by emitting energyemitting energy

Unaffected by temperature, Unaffected by temperature, pressure, or catalystpressure, or catalyst

Nuclear stabilityNuclear stability

More stable nuclei haveMore stable nuclei have Low atomic number: > 83 are Low atomic number: > 83 are

radioactiveradioactive Ratio of neutrons to protons is 1:1Ratio of neutrons to protons is 1:1 Even number of protons and neutronsEven number of protons and neutrons

Types of radiationTypes of radiation

Alpha Alpha ((αα)) low penetrating power low penetrating power

Beta (Beta (ββ) moderate ) moderate penetrating penetrating power power

Gamma (Gamma (γγ) high ) high penetrating power penetrating power

He42

e01

Transmutation- change in no. Transmutation- change in no. of protons, creating a new of protons, creating a new

elementelementParticle Particle emittedemitted

Mass numberMass number Atomic Atomic numbernumber

alpha alpha ((αα)) -4-4 -2-2

beta (beta (ββ)) samesame +1+1

positronpositron samesame -1-1

neutronneutron -1-1 samesame

proton proton -1-1 -1-1

K-capture K-capture (add e(add e--))

samesame -1-1

He42

n10

e01e01

p11

Electric charge and mass Electric charge and mass numbers are conservednumbers are conserved

An alpha particle is capturedAn alpha particle is captured

A beta particle is emittedA beta particle is emitted

FHeN 189

42

147

eNpU 01

23993

23992

An alpha particle is emittedAn alpha particle is emitted

Beta emissionBeta emission

?42

21483 HeBi Tl210

81

?6630

6629 ZnCu e01

Half lifeHalf life

The time it takes for half of the nuclei The time it takes for half of the nuclei to decay.to decay.

Carbon-14 emits beta radiation and Carbon-14 emits beta radiation and decays with a half-life of 5730 years. decays with a half-life of 5730 years. If you start with 2.00 x 10If you start with 2.00 x 10-12-12

grams of grams of carbon-14, how many grams remain carbon-14, how many grams remain after 3 half lives?after 3 half lives?

2.00 x 102.00 x 10-12-12 g x ½ x ½ x ½ = .250 x 10 g x ½ x ½ x ½ = .250 x 10--

1212gg

Phosphorus-32 has a half-life of 14.3 Phosphorus-32 has a half-life of 14.3 days. How many milligrams of days. How many milligrams of phosphorus-32 remains after 57.2 phosphorus-32 remains after 57.2 days if you start with 4.0 mg of the days if you start with 4.0 mg of the isotope?isotope?

57.2 days is how many half lives? 57.2 days is how many half lives?

57.2/14.3= 4 half lives57.2/14.3= 4 half lives

4.0 (1/2)4.0 (1/2)44 = 0.25 mg = 0.25 mg

A 0.456 mg sample of hydrogen-3 A 0.456 mg sample of hydrogen-3 was collected. After 24.52 years, was collected. After 24.52 years, 0.114 mg of the sample remains. 0.114 mg of the sample remains. What is the half-life of hydrogen-3?What is the half-life of hydrogen-3?

0.1140.114 == 11 == 11

0.456 4 20.456 4 2

Two half lives!Two half lives!

24.52/2 = 12.26 years24.52/2 = 12.26 years

2

Applications of nuclear Applications of nuclear energyenergy

Power plantsPower plants WeaponsWeapons MedicineMedicine

Diagnosis (imaging)Diagnosis (imaging) Treatment (killing tumors)Treatment (killing tumors)

Nuclear energyNuclear energy

Mass is NOT conserved in a nuclear Mass is NOT conserved in a nuclear reaction, but mass-energy is.reaction, but mass-energy is.

E = mcE = mc2 2 Converts the “lost” mass into energyConverts the “lost” mass into energy

Fission- breaking apart of a Fission- breaking apart of a nucleusnucleus

Can cause a chain reaction

Nuclear energyNuclear energy

Control rods slow or stop the chain Control rods slow or stop the chain reaction by absorbing neutrons reaction by absorbing neutrons (made of boron or cadmium)(made of boron or cadmium)

fuel fuel Coolant (water) absorbs and Coolant (water) absorbs and

transfers the heat energy.transfers the heat energy. Containment vessels keep Containment vessels keep

radioactive material from escaping.radioactive material from escaping.

PuorU 23994

23592

Nuclear reactorNuclear reactor

Containment building

Cooling water

Enriching UraniumEnriching Uranium

Spent fuel rods stored on Spent fuel rods stored on sitesite

Nuclear power plants in the Nuclear power plants in the U.S.U.S.

State Percent

Vermont    72.3

New Jersey    55.1

Connecticut    53.4

South Carolina    52.0

Illinois    48.7

New Hamphshire    44.1

Virginia    39.6

Percentage of state’s electricity that is nuclear (2009)31 states have

nuclear reactors

Nuclear power plants provides 17% of the Nuclear power plants provides 17% of the world's electricity. world's electricity.

In France, about 75% of the electricity is In France, about 75% of the electricity is generated from nuclear power. generated from nuclear power.

In the United States, nuclear power supplies In the United States, nuclear power supplies about 20% of the electricity overall. about 20% of the electricity overall.

There are more than 400 nuclear power plants around the world, with more than 100 in the United States.

Chernobyl - April 1986Chernobyl - April 1986

50 deaths immediately

4000 deaths from cancer

March 12, 2011

Fukushima, Japan

Since April 2011, Germany decided Since April 2011, Germany decided to replace nuclear power with to replace nuclear power with renewable energy sources within a renewable energy sources within a decade. decade.

FusionFusion

Happens on the sun

Fusion PowerFusion PowerBenefitsBenefits abundant fuel (deuterium)abundant fuel (deuterium) No greenhouse gases emittedNo greenhouse gases emitted

DrawbacksDrawbacks Extremely high temperatures required Extremely high temperatures required

150 000 000° Celsius!!! 150 000 000° Celsius!!! Challenging to contain high-energy plasmaChallenging to contain high-energy plasma

ITERITER - - IInternational nternational TThermonuclear hermonuclear EExperimental xperimental RReactoreactor

Nuclear WeaponsNuclear Weapons

Atomic bomb- fission reactionAtomic bomb- fission reaction Used in WWIIUsed in WWII

Hydrogen bomb- fusion reactionHydrogen bomb- fusion reaction Developed in 1951Developed in 1951

““Little Boy” dropped on Little Boy” dropped on Hiroshima, Japan Aug. 6, Hiroshima, Japan Aug. 6,

19451945

contained 64 kg of uranium (141lbs)Equivalent to 18,000 tons of TNT- fission reaction

““Fat Man” dropped on Fat Man” dropped on Nagasaki, Japan Aug. 9, Nagasaki, Japan Aug. 9,

19451945

around 200,000 died total

Nuclear bomb videosNuclear bomb videos

http://science.howstuffworks.com/http://science.howstuffworks.com/nuclear-bomb.htmnuclear-bomb.htm

http://science.howstuffworks.com/http://science.howstuffworks.com/nuclear-bomb4.htmnuclear-bomb4.htm

Nuclear medicineNuclear medicine

Diagnostic tests

Myocardial perfusion scan with Thallium-201

stress images (top)

rest images (bottom)

TherapiesTherapies -sodium iodide for -sodium iodide for

hyperthyroidism hyperthyroidism and thyroid cancerand thyroid cancer

-implanted -implanted capsules of capsules of isotopes to treat isotopes to treat cancercancer

-gamma radiation -gamma radiation to kill tumorsto kill tumors