Chapter 22 – Nuclear Chemistry. Nuclear Symbols Element symbol Mass number (p + + n o ) Atomic...
-
Upload
brian-hernandez -
Category
Documents
-
view
231 -
download
0
Transcript of Chapter 22 – Nuclear Chemistry. Nuclear Symbols Element symbol Mass number (p + + n o ) Atomic...
Chapter 22 – Nuclear Chapter 22 – Nuclear ChemistryChemistry
Nuclear SymbolsNuclear Symbols
23592U
Element symbol
Mass number (p+ + no)
Atomic number(number of p+)
Types of Radioactive DecayTypes of Radioactive Decay
alpha production (alpha production (): helium ): helium nucleusnucleus
beta production (beta production (): ):
92238
24
90234U He Th
90234
91234
10Th Pa e
24
He
10 e
2+
Alpha Alpha RadiationRadiation
Limited to VERY large nucleii.
Beta Beta RadiatioRadiatio
nn
Converts a neutron into a proton.
Types of Radioactive DecayTypes of Radioactive Decay
gamma ray production (gamma ray production ():):
positron production :positron production :
electron capture: (inner-orbital electron capture: (inner-orbital electron is captured by the nucleus)electron is captured by the nucleus)
92238
24
90234
002U He Th
1122
10
1022Na e Ne
80201
10
79201
00Hg e Au
10 e
Types of RadiationTypes of Radiation
Deflection of Decay ParticlesDeflection of Decay Particles
Opposite charges_________ each other.
Like charges_________ each other.
attract
repel
NuclearNuclearStabilityStability
Decay will occur in such a way as to return a nucleus to the band (line) of stability.
Half-life ConceptHalf-life Concept
Sample Half-LivesSample Half-Lives
A A Decay Decay SeriesSeries
A radioactive nucleus reaches a stable A radioactive nucleus reaches a stable state by a series of stepsstate by a series of steps
Nuclear Fission and FusionNuclear Fission and Fusion
•FusionFusion:: Combining two light nuclei Combining two light nuclei to form a heavier, more stable to form a heavier, more stable nucleus.nucleus.
•FissionFission: : Splitting a heavy nucleus Splitting a heavy nucleus into two nuclei with smaller mass into two nuclei with smaller mass numbers.numbers.0
192
23556
1423691
013n U Ba Kr n
23
11
24
10He H He e
Energy and MassEnergy and MassNuclear changes occur with small but Nuclear changes occur with small but measurable losses of mass. The lost mass measurable losses of mass. The lost mass is called the mass defect, and is converted is called the mass defect, and is converted to energy according to Einstein’s equation:to energy according to Einstein’s equation:
E = E = mcmc22
mm = mass defect = mass defect
EE = change in energy = change in energy
cc = speed of light = speed of light
Because c2 is so large, even small amounts of mass are converted to enormous amount of energy.
FissionFission
Fission ProcessesFission Processes
Event
NeutronsCausingFission Result
subcritical < 1 reaction stopscritical = 1 sustained reactionsupercritical > 1 violent explosion
A self-sustaining fission process is A self-sustaining fission process is called a chain reaction.called a chain reaction.
A Fission ReactorA Fission Reactor
FusionFusion