WorksheetsHalf life practice problems
Total questions: 18
Worksheet time: 12mins
Name
Class
Date
1.
What is Half-life?
a)
The amount of time it takes for some of the nuclei in a sample of the isotope to decay
b)
The amount of time it takes for half the electrons in a sample of the isotope to decay
c)
The amount of time it takes for half the nuclei in a sample of the isotope to decay
d)
the amount of time it takes to double the nuclei in a sample of the isotope to decay
2.
The half-life of Zn-71 is 2.4 minutes. If one had 100.0 g at the beginning, how many grams would be left after 7.2 minutes has elapsed?
a)
100.0g
b)
50.0g
c)
12.5g
d)
8.5g
3.
After the third half-life, how much of the sample is left?
a)
1/2
b)
1/3
c)
1/16
d)
1/8
4.
The half life of iodine-131 is 8.040 days. What percentage of an iodine-131 sample will remain after 40.20 days?
a)
312.5%
b)
31.25%
c)
.3125%
d)
3.125%
5.
Barium-122 has a half-life of 2 minutes. A fresh sample weighing 80 g was obtained. If it takes 10 minutes to set up an experiment using barium-122, how much barium-122 will be left when the experiment begins?
a)
0.25g
b)
2.5g
c)
25g
d)
80g
6.
The half-life of strontium-90 is 25 years. How much strontium-90 will remain after 100 years if the initial amount is 4.0 g?
a)
3.0g
b)
0.25mg
c)
0.3g
d)
0.25g
7.
How many protons does U 235 atom have ?
a)
235
b)
92
c)
143
d)
67
8.
The radiation detected from a piece of rock is reduced significantly when the rock is wrapped in foil. What type of radiation is being emitted?
a)
Alpha
b)
Beta
c)
Gamma
d)
none of the above
9.
The beta particle has a charge of ...........
a)
+1
b)
-1
c)
-2
d)
+4
10.
Uranium-238 decays into Thorium-234 by emitting .........
a)
an alpha particle
b)
a beta particle
c)
gamma rays
d)
visible light
11.
Which type of nuclear radiation is being emitted here?
a)
alpha
b)
beta
c)
gamma
d)
none
12.
Nuclear fission is when scientists put atoms together.
a)
True
b)
False
13.
Gamma rays damage human cells/tissue.
a)
True
b)
False
14.
When nuclei decay, massive amounts of __________ is released.
a)
energy
b)
jello
c)
protons
d)
neutrons
15.
When an element loses protons, its __________changes.
a)
protonic number
b)
electronic number
c)
neutronic number
d)
atomic number
16.
What is this sketch
showing?
showing?
a)
Nuclear fusion
b)
Nuclear action
c)
Nuclear chain
d)
Nuclear chain reaction
17.
What makes an element radioactive?
a)
When it's nuclei expands
b)
When it's electrons explode
c)
When it's nuclei behave
d)
When it's nuclei decay
18.
This is when scientists split the nuclei of atoms with neutrons.
a)
Nuclear fission
b)
Nuclear fusion
c)
Nuclear power
d)
Nuclear weapon
100 %
