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WorksheetsHalf-lives quiz
Total questions: 10
Worksheet time: 47mins
Name
Class
Date
1.
Iodine-131 is used to destroy thyroid tissue in the treatment of an overactive thyroid. The half-life of I-131 is 8 days. How much of a 60 g sample of I-131 will remain after 24 days?
a)
15 g
b)
7.5 g
c)
30 g
d)
3.75 g
2.
Technetium-99 is used for brain scans. If only 12.5 g remains from a 200 g sample. How long ago was the sample received? (The half-life of Technetium-99 is 6 hours)
a)
24 hours
b)
30 hours
c)
18 hours
d)
36 hours
3.
A lab orders 32 grams of Mercury-197. When the sample arrives 15 days later only 1 g of the isotope remains. How long is the half-life of Hg-197?
a)
5 days
b)
7.5 days
c)
3.75 days
d)
3 days
4.
The half-life of Sr-90 is 25 years. How much of a 4.0 g sample of Sr-90 will remain after 100 years?
a)
2 g
b)
0.25 g
c)
1 g
d)
0.5 g
5.
If the half-life of uranium-232 is 70 years, how many half-lives will it take for a 10 g sample to decay to 1.25 g?
a)
3
b)
4
c)
23.33
d)
210
6.
12 mg of Technetium-99 is injected into a patient and starts to decay. 24 hours later 0.75 mg remains. How long is the half-life of Tc-99?
a)
4 hours
b)
8 hours
c)
12 hours
d)
6 hours
7.
How long would it take for a 16 g sample to decay to 0.25 g if the half life of the element is 1500 years?
a)
7500 years
b)
250 years
c)
9000 years
d)
10500 years
8.
How many half-lives would it take for a 256 g sample to decay to 1 g?
a)
6
b)
7
c)
8
d)
9
9.
What percent of a radioactive isotope will be left after three half-lives?
a)
25%
b)
50%
c)
12.5%
d)
33.33%
10.
Which of the following elements is most likely radioactive? (Hint: look at where the elements are on the periodic table)
a)
Beryllium (Be)
b)
Calcium (Ca)
c)
Strontium (Sr)
d)
Radium (Ra)
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