Unit 3 – Nuclear Chemistry
1. Write “isotopic symbols” for:
alpha, 
2.
238
92
U 
3.
234
90
Th 
4.
234
91
Pa 
5.
220
86
Rn 
6.
216
84
Po 
7.
14
6
8.
210
83
9.
1
0
10.
23
12
C 
234
90
14
7
Bi 
n +
10
5
Th +
234
91
Pa +
beta, 


positron, 
( _ beta _ decay)
+
4
2
He
( alpha decay)
+
4
2
He
( alpha decay)
+
0
1
e
( beta decay)
N +
( _beta_ decay)
+
+
+
neutron, n
( _alpha_ decay)




 

 
B 
Mg 
gamma, 
4
2
( beta decay)
He
+ 00 
( neutron bombardment w/alpha emission)
( positron decay w/gamma emission)
11. Write equations for the following reactions:
a. The production of 56Mn by neutron bombardment of 55Mn.
b. The production of the new element dubnium by bombarding elements of
nuclei.
c. The bombardment of 27
13 Al with particles to produce
to silicon by positron emission.
31
15
249
98
Cf with
15
7
N
P and the subsequent decay of
d. The conversion of potassium-40 to argon-40 by electron capture.
e. The production of carbon-14 in the upper atmosphere by neutron bombardment of
f.
Uranium-238 that undergoes a series of 4 alpha emissions and one beta emission.
12. According to the above data, what is the half-life of the substance?
13. What percent of the original sample remains after 4 hours?
14. Sketch on the graph above, a curve for a substance whose half-life is 2.0 hrs.
15. Iodine-131 has a half-life of 8 days. What percent of a sample remains after 24 days?
13
6
C.
31
15
P