Nuclear Notes.notebook
May 18, 2017
NUCLEAR CHEMISTRY
235
U
92
NATURAL RADIOACTIVE DECAY
Radiation ­­ Energy or particles emitted from a source.
"Nuclear binding energy" varies
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Nuclear Notes.notebook
May 18, 2017
Radioactive elements ­­ isotopes of an atom with an unstable nucleus.
(too many or too few neutrons)
EX: Carbon­12
(stable)
Carbon­14
(unstable/ radioactive)
6p+
6p+
6n°
8n°
All radioactive elements decay naturally into OTHER ELEMENTS.
­­rate varies:
microseconds to billions of yrs.
­­rate of decay cannot be altered.
"half­life"
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Nuclear Notes.notebook
May 18, 2017
Geiger Counter
­­detects radiation
­­developed by:
Hans Geiger
Walter Müller
Transuranic Waste Casks
(Originated from Nevada...destined for Carlsbad, NM
This image is available from the National Nuclear Security Administration Nevada Site Office Photo Library under number 11198­16 3
Nuclear Notes.notebook
May 18, 2017
"Fiesta Ware" dishes: previously made with uranium oxides This image was originally posted to Flickr by lostinmiami athttp://flickr.com/photos/36675979@N08/5916156200. It was reviewed on 3 October 2012 by the FlickreviewR Alpha Particle
4
Symbol: α or He 2
222
Equation: 88 Ra
→ 218
4
86
2 He + Rn 4
Nuclear Notes.notebook
May 18, 2017
ALPHA EMISSION
­­8000X more massive than beta
­­poor penetrating power
­­can be stopped by air and paper
­­cannot penetrate skin
­­radioactive nucleus loses 2 p+ and 2 no
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Nuclear Notes.notebook
May 18, 2017
Beta Particle
0
Symbol: β or e ­1
234
Equation: 90 Th
234
0
→ ­1 e + Pa 91
BETA EMISSION
­­fast moving e­
­­better penetrating power
­­stopped by Al
­­neutron splits:
1
n
0
0
e
­1
+
ejected @
high speeds
1 p
1
stays in
nucleus
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Nuclear Notes.notebook
May 18, 2017
DECAY SERIES FOR Th­232
http://hyperphysics.phy­astr.gsu.edu/hbase/nuclear/radser.html#c1
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Nuclear Notes.notebook
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Gamma Ray
0
Symbol: or 0
238
234
4
0
Equation: 92 U → 2 He + Th + 2 90
0
GAMMA EMISSION
­­High energy electromagnetic waves
­­Often accompanies α or β decay
­­Good penetrating power
­­Pb or concrete to stop
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Nuclear Notes.notebook
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Nuclear Notes.notebook
May 18, 2017
Positron Emission
0
Symbol: e +1
1
1
p
same mass as e­ but
opposite charge
1
0
0
n + e
+1
0
22
22
Equation: 11 Na→ + e + Ne 10
1
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Nuclear Notes.notebook
May 18, 2017
http://www.bioimaging.fi/methods/pet­mri/
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F­FDG
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Nuclear Notes.notebook
May 18, 2017
http://radiologylouisville.com/imaging­services/positron­emission­tomography­pet/
http://www.pnas.org/content/97/16/9226.figures­only
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Nuclear Notes.notebook
May 18, 2017
Electron Capture
0
Symbol: e ­1
0
1
1
0
­1 e + p n
1
0
201
0
201
Equation: 80 Hg + e → 79
Au + 0 ­1
gamma rays
always accompany
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