Name: __________________________
Date: ____________________
Isotopes Worksheet 2
1. What is an isotope? How can you tell them apart? They are different versions
of the same element. They have a different # of neutrons.
2. What does the number next to isotopes signify? The atomic mass
3. For each of the following isotopes, write the number of protons, neutrons
and electrons.
#p+
#n°
#e-
Chromium-58
24
32
24
Chromium-63
24
39
24
#p+
#n°
#e-
Carbon-12
6
6
6
Carbon-16
6
10
6
#p+
#n°
#e-
Nitrogen-15
7
8
7
Nitrogen-20
7
13
7
#p+
#n°
#e-
Sulfur-23
16
7
16
Sulfur-25
16
9
16
#p+
#n°
#e-
Sodium-12
11
1
11
Sodium-20
11
9
11
#p+
#n°
#e-
Selenium-50
34
16
34
Selenium-55
34
21
34
4. Fill in the isotope names and any missing information, including isotope numbers
from the chart. Use your periodic table and the information provided.
#p+
#n°
#e-
Manganese-42
25
17
25
Manganese-40
25
15
25
#p+
#n°
#e-
Germanium-62
32
30
32
Germanium-64
32
32
32
#p+
#n°
#e-
Palladium-94
46
48
46
Palladium-97
46
51
46
Cesium-168
Cesium-166
#p+
#n°
#eSymbol
17O8
131Xe54
207
82PB
23Na11
88Sr38
24Ne10
238
92U
55
113
55
Name of the element
Oxygen-17
55
111
55
Atomic #
Xenon-131
8
54
Lead-207
82
Sodium-23
11
Stronium-88
38
Neon-24
10
Uranium-238
92
#p+
#n°
#e-
Mass #
8
9
8
17
54
77
54
131
82
125
82
207
11
12
11
23
38
50
38
88
10
14
10
24
92
146
92
238