Nuclear Chemistry Worksheet
Name______________________________________ Date____________ Block____
Most nuclear reactions involve changes in the number of protons and/or neutrons in the
nucleus of an atom. These changes are called transmutations because an atom of one element is
changed into an atom of a different element. During these changes, nuclear particles may be
absorbed and/or emitted along with a release of energy.
There are four types of nuclear reactions:
1) natural radioactive decay: transmutations occur by natural radioactivity (the ability of a nucleus
to emit a nuclear particle and energy without external stimulation);
2) artificial transmutation: transmutations occur by nuclear disintegration caused by external
stimulation as a scientist bombards a nucleus with a particle (the addition of another nuclear
particle makes the nucleus unstable);
3) fission: certain nuclei having a large mass are bombarded with special particles that cause
the nuclei to split into two nuclei each having a smaller mass;
4) fusion: nuclei of light elements are combined to form heavier nuclei.
Nuclear reactions are written using symbols in the maX notation. The symbols for the major
nuclear particles involved in nuclear reactions are given below.
Alpha particle
4
Proton
1
Neutron
1
Electron
0
Positron
0
Gamma ray
0
He (an alpha particle is a helium nucleus)
2
1
H (the most common hydrogen nucleus is a proton)
n
0
e
or
1
e
or
0

-1
0
-1
0
1

(also called a beta particle)

The table below contains information about nuclear reactions involving the emission of
radiation.
Type of Reaction
Alpha emission ()
Beta emission ()
Positron emission (+)
Gamma emission
Electron capture (EC)
Radiation
(Particle)
4
2
He
or
-1e
0
or
1e
0
0
0
or
-1e
0
0


-1
0
1
0
-1

NUCLEAR CHANGES
Effect on the
Effect on the
Atomic Number
Atomic Mass
decrease by 2
decrease by 4
increase by 1
no change
decrease by 1
no change
no change
no change
decrease by 1
no change
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Nuclear Chemistry Worksheet
Nuclear reactions that involve bombardment of nuclei vary in their products. For example:
9
Be +
4
14
7
4
2
4
N +
27
13
Al
45
21
He 
2
1
1
+
Sc +
He 
1
H 
n 
0
12
6
C +
17
8
1
0
O +
26
13
n
1
1
Al +
42
19
K +
H
2
1
4
2
H
He
In nuclear equations, the total number of positive charges (represented by the atomic numbers)
of the reactants (substances on the left of the reaction arrow) equals the total number of
positive charges of the products (substances on the right of the reaction arrow). The total
mass of the reactants must also equal the total mass of the products.
For example:
A uranium-238 atom decays by emitting an alpha particle to form a thorium-234
atom.
238
234
4
92U 
90 Th +
2 He
Another example:
Potassium-40 decays to calcium-40 by beta emission.
40
40
0
19K 
20Ca + -1β
In both examples, the total mass on the left equals the total mass on the right.
The total number of positive charges on the left equal the total number of
positive charges on the right.
Write out or complete the following nuclear reactions.
1) Technetium-99 (9943 Tc) decays by beta emission to form ruthenium-99
(9944 Ru).
2)
Phosphorus-32 decays by beta emission to form sulfur-32.
3)
Francium-212 (21287 Fr) decays by alpha emission.
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Nuclear Chemistry Worksheet
4)
Fluorine-18 decays to oxygen-18 by positron emission.
5)
Sodium-24 decays by beta emission.
6)
Krypton-76 absorbs a beta particle to form bromine-76.
7)
Aluminum-27 absorbs an alpha particle to form phosphorus-30 and emits a
neutron.
8)
Nitrogen-14 absorbs an alpha particle to form oxygen-17 and emits a
proton.
9)
When neptunium-239 decays, plutonium-239 is formed and a particle is
emitted. (Be sure to include the correct particle in the equation.)
10) A particular atom absorbs a neutron to form uranium-236. No particle is
emitted.
Complete the following nuclear equations:
11) ________ 
12) ________ +
13)
239
93
14)
4
15)
1
Np 
239
0
4
2
94
e +
14
He 
12
-1
7
6
N
C +
1
0
n
Pu + _________
2
He + _________ 
240
0
n + __________ 
236
94
Pu +
92
1
U
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0
n +
1
0
n
Nuclear Chemistry Worksheet
16)
13
7
N  _________ +
1
17) ______ +
1
18) ______ +
19)
226
88
20)
18
21)
49
22)
239
94
23)
7
24)
3
25)
14
26)
9
27)
14
28)
26
29)
59
30)
208
84
9
24

Ra

F
Cr
7
1
H +
2
n

6
3
3
1
H
+
_________
+
Li 
1
C 
14
4
2
27
Co +
Po 
7
222
0
-1
+1
2
86
He
Rn
e
e
241
95
1
Am +
1
H +
He + ___________
12
He 
1
He
4
+
0
2
1
+
0
n
N + _________
He 
N +
Mg +
2
4
H  _________
4
2
12
4
e
C +
_______ +
Be +
7
0
12
+1
Pu + _________ 
Li +
4
H 
_______

3
6
1
0
n 
0
2
1
H

6
C + _________
_________
________
0
+
+
0
+1
________ +
________ +
4
2
+1
He
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e
e
0
+1
e
1
0