Chemistry Reference
In-Depth Information
The following equation shows an example of an artificial transmutation, as
curium-244 is bombarded with carbon-12 to form nobelium-254:
12
6
C +
244
96
Cm
254
102
No + 2
1
0
n
Perhaps you are familiar with the terms nuclear fission and nuclear fu-
sion. Nuclear fission is the process by which a relatively massive nucleus is
divided into smaller nuclei and one or more neutrons. Nuclear fission is
the process that generates so much power in nuclear power plants and in
certain types of nuclear weapons, such as the bombs that were dropped on
Japan in 1945. The following equation shows an example of nuclear fission
(the nuclear fission of uranium-235):
235
92
U +
1
0
n
90
38
Sr +
143
54
Xe + 3
1
0
n
Notice there are neutrons on both sides of the equation. The neutron
on the left side of the equation can be thought of as the projectile that
causes the larger atom to “split.” The three neutrons that are released on
the right side of the equation can then, under the proper conditions, go on
to “split” more atoms, releasing still more neutrons in the process. This
sets up the process that is called a chain reaction.
Nuclear fusion is the process of less massive nuclei combining into more
massive ones. Nuclear fusion is the process that powers stars, including our
sun, with hydrogen nuclei combining to produce helium nuclei, according
to a series of reactions represented by the equations that follow:
1
1
H +
1
1
H
1
+1
e
2
1
H +
1
1
H +
2
1
H
3
2
He
3
2
He +
3
2
He
4
2
He + 2
1
1
H
3
2
He +
1
1
H
0
+1
e
4
2
He +
You will probably be called upon to balance nuclear reactions. One
common type of question is shown in the following.
Example 1
Identify the particle represented by X and complete each of the
following nuclear equations.
A.
238
92
U
234
90
Th + X
1
1
p
B.
26
12
Mg +
4
2
He + X
239
94
Pu + X
C.
240
94
Pu
