Section #: 21.3
Absolute-Age Dating of Rocks
Practice Test
1.
What isotope is used for finding the age of materials that are organic in origin?
a.
thorium-232
b.
carbon-14
c.
potassium-40
d.
uranium-238
Hint
2.
What method is used to determine the exact age of a rock or fossil?
a.
dendrochronology
b.
radiometric dating
c.
the principle of superposition
d.
relative age dating
Hint
3.
According to the figure, after four half-lives (22,820 years), how much C-14 would be left?
a.
0%
b.
6.25%
c.
10%
d.
25%
Hint
4.
A gravel-sized particle in a conglomerate is __________ the conglomerate rock.
a.
older than
b.
younger than
c.
the same age as
d.
always ten times older than
Hint
5.
What type of material is used in the dating technique of dendrochronology?
a.
key beds
b.
tree growth rings
c.
tree leaves
d.
sediment layers from lake beds
Hint
6.
According to the table, what is the half-life of Thorium-234?
Days Elapsed
Grams Of Thorium – 234 Remaining
0
16
12
11
24
8
36
6
a.
8 days
b.
16 days
c.
20 days
d.
24 days
Hint
