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Nuclear Chemistry
Chapter 21
Nuclear Chemistry
Study of nuclear reactions and their uses in chemistry
nuclear reactions – change in matter originating in the nucleus of an atom
radioactive – nuclei spontaneously changing and emitting radiation
Nuclear Chemistry
Subatomic particles are involved proton and neutron nucleons
Can be determined by atomic number and mass number
Same atomic number, different mass number isotope
Radioactive nuclei radionuclide Atoms with radionuclides radioisotopes
Nuclear Chemistry
Radionuclides Unstable Emit particles and electromagnetic
radiation Radioactive decay
Radioactive Decay
1 – alpha radiation α Helium - 4 particles, aka alpha particles 4
2He
23892U 234
90Th + 42He
Alpha radiation - Sample
What product is formed when radium-226 undergoes alpha decay?
22688Ra 222
86Rn + 42He
What element undergoes alpha decay to form lead-208?
21284Po 208
82Pb + 42He
Radioactive decay
2 – beta radiation β High speed e- 0
-1e or 0-1 β
13153I 131
54Xe + 0-1e
Radioactive decay
3 – gamma radiation γ High energy photons 0
0γ Energy lost when nucleons reorganize
Radioactive decay
4 – positron emission Same mass as e-, opposite charge 0
1e
116C 11
5B + 01e
Positron can convert proton to neutron
Radioactive decay
5 – electron capture Capture of electron by nucleus from
electron cloud 0
-1e consumed, not formed
Electron Capture - Sample
Write nuclear equations for the following processes: a) Mercury-201 undergoes electron
capture b) Thorium-231 decays to form
protactinium-231 a) 201
80Hg + 0-1e 201
79Au
b) 23190Th 231
91Pa + 0-1e
Electron Capture-Sample 2
Write a balanced nuclear equation for the reaction in which oxygen-15 undergoes positron emission 15
8O 157N + 0
1e
Nuclear Transmutations
Nuclei changed by being struck by neutron or nucleus
Commonly represented by listing in order the target nucleus, the bombarding particles, the ejected particles, the product nucleus 14
7N (α,p)178O
147N + 4
2He 11p + 17
8O
Nuclear Transmutations-Sample
Write the balanced nuclear equation for the process summarized as 27
13Al (n, α) 24
11Na 27
13Al + 10n 4
2He + 2411Na
Using shorthand notation, write the nuclear reaction 16
8O + 11H 13
7N + 4
2He 16
8O (p, α) 42He
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