Introduction to Nuclear Chemistry Chapter 19. I. Study of Nuclear Reactions Nuclear Reactions vs....
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Transcript of Introduction to Nuclear Chemistry Chapter 19. I. Study of Nuclear Reactions Nuclear Reactions vs....
Introduction to Nuclear Chemistry
Chapter 19
I. Study of Nuclear Reactions
Nuclear Reactions vs. Chemical ReactionsDefine “ Chemical Reaction”?
RnparticlealphaRa 22286
22688
Define “Nuclear Reaction”Reaction involving spontaneous emission of radiation by an unstable nuclei to a more stable nuclei of a different element.
Involves changes within nucleus.Atoms of each element do not balance.Spontaneous change of a radioisotope.
RnparticlealphaRa 22286
22688
RnparticlealphaRa 22286
22688
II. Types of Nuclear Radiation **Responsible for properties of top three!!
Example Nuclear Reactions:
RnRa 22286
42
22688 He
NpeU 23993
01-
23992
* 23090
00
23090 ThTh
Rules For Balancing Nuclear Reactions:
1. The sum of the mass numbers of the reactants must equal the sum of the mass number of the products.
*Total # nucleons remain the same.
2. The sum of the atomic numbers of the reactants must equal the sum of the mass number of the products.
* Electrical charge remains the same.
What kind of radiation is produced in the following nuclear reaction?
? 21884
22286 PoRn ? 218
8422286 PoRn
III. Radioactive Decay Rates
Follows First Order KineticsCommonly described by “half-life”.
t1/2
“The time required for half the radioactive atoms in a sample to undergo decay.”
Derived From Integrated Rate Law:
ktA
A
o
t-
][
][ln
ktoAtA
][
][ln kt
oAtA
][
][ln
kt0.693
2/1
Examples of Half-Lives
Iodine-131 (t1/2 = 8 days)
Example Problem:
The value of t1/2 for I-131 is 8 days.
How many I-131 atoms will remain after 24 days in a sample originally containing
6.4 x 1016 I-131 atoms?
