Atomic Theory WS 5
Nuclear Chemistry Review Sheet
A.
Completion
Use this completion exercise to check your knowledge of the terms and your understanding of the
concepts introduced in this unit. Each blank can be completed with a term, short phrase, or number.
Isotopes with unstable nuclei are ______________ . The ______________ of these radioisotopes decay
to _________ nuclei plus ______________. The radiation may be alpha, _________, or gamma. __________
radiation consists of positively-charged particles (_________ nuclei) that are easily stopped by a sheet of paper.
Beta radiation is composed of fast-moving particles, which are ____________, and therefore have almost no
__________. ________________ radiation is a form of electromagnetic radiation which has much more energy
than _________________________. Gamma radiation has no ____________ nor _____________. Two other
types of radiation , ________________ and ________________ reduce the neutron:proton ratio in the nucleus.
Nuclear _______________ occurs when fissionable isotopes are bombarded with ___________. An
example is U- ______, but not U-_______. _______________ , an element artificially-produced from uranium238, responds the same way. The radioisotopes split into many fragments, many of which are also
_______________. In the process they produce more ______________, which maintain the reaction, and
_____________ which can be harnessed.
In nuclear ____________, small nuclei fuse to make _________________ nuclei. The sun’s
____________ is produced when _____________ nuclei fuse to make _________________ nuclei. Fusion
releases even more energy than fission, but it usually does not release _____________________.
Nuclear ____________ are used to make new elements in the lab. The superheavy elements are made
by smashing the nuclei of smaller ____________ together.
B.
True-False
Classify each of these statements as always true (AT); sometimes true (ST); or never true (NT).
_______ 1. Beta radiation is emitted when a radioisotope decays.
_______ 2. Gamma radiation has a negative charge.
_______ 3. Gamma radiation is high-energy electromagnetic radiation.
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Atomic Theory WS 5
_______ 4.
238
92U
+
-1
0

239
92U.
_______ 5. In nuclear fusion the nuclei of two very large atoms fuse to make a heavier nucleus.
_______ 6. The products of nuclear fission are never radioactive.
_______ 7. When a beta particle is emitted, the atomic number increases by 1, and the mass number stays
the same.
_______ 8. When a radioactive nucleus emits an alpha particle, its atomic number decreases by 4, and its
mass number decreases by 2.
_______ 9. When a gamma ray is emitted, the atomic mass and atomic number both increase.
_______ 10. Transuranium elements have atomic numbers greater than 92.
C.
Problems
Solve the following problems in the space provided. Show your work.
1. Write the nuclear equations for these processes.
a. the alpha decay of 21884Po
b. the beta decay of 21082Pb
2. Complete the following transmutation equations:
a.
9
b.
238
92U
c.
15
4Be
6C
+
+
1
1H
4
+
1

2He
0n
4
2He
+ ____________
 2 10n + ____________
 ___________
3. Write nuclear equations for the following transmutations:
a. the fusion of plutonium-242 and neon-22. One of the two products is four separate neutrons.
b. the decay of uranium-239. One of the two products is one beta particle.
adapted from Addison-Wesley Chemistry, 1987
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