Summary Worksheet-Parts of an Atom
1. List two ways that a proton differs from an electron.
Mass (proton is massive compared to the electron)
Charge (electrons are -, protons are +)
2. Which subatomic particle determines a specific element?
# of protons
3. a. What is the mass number of an element that contains 20 protons and 22 neutrons?
42
b. Which element is this?
Ca
4. a. How are isotopes of a particular element different from each other?
Different # of neutrons
b. How are they similar?
Same # of protons
5. Write the symbol for calcium-41, including its mass number and atomic number.
41
Ca
20
6. An atom of zinc has an atomic number of 30 and a mass number of 65. How many protons, electrons, and neutrons are
present in this zinc atom?
P = 30, e- = 30, n = 35
7. How does the number of electrons compare to the number of protons in a/an:
a. neutral atom?
They are equal
b. ion with a -2 charge?
There are 2 extra electrons8. 1 atomic mass unit (amu) = 1.66054x10 -27 kg, Mass of an electron = 9.10939x10-31 kg, Mass of a proton = 1.67262x10-27
kg, Mass of a neutron = 1.67493x10-27 kg
37[5.4858E-4] + 37[1.00727] + 50[1.00866] = 87.722amu
37[5.4858E-4] + 37[1.00727] + 48[1.00866] = 85.705amu
9. Titanium has five common isotopes: 4622Ti (8.0%), 4722Ti (7.8%), 4822Ti (73.4%), 4922Ti (5.5%), 5022Ti (5.3%). What is the
average atomic mass of titanium?
0.08[46.3799] + 0.078[47.3885] + 0.734[48.347] + 0.055[49.406] + 0.053[50.4145] = 48.31894 amu
10.Complete the table for the following isotopes.
Isotope
Atomic
number
Molybdenum-92
42
Mass
Number
92
Symbol
92
Mo
Technetium-96
43
96
43
Manganese-55
25
55
55
Tc
Mn
11. List the number of protons, neutrons and electrons in each of the following atoms.
Atom
Protons
Neutrons
Electrons
14
C
6
8
6
17 2O
8
9
10
3
H
1
2
1
12. Fill in the blanks
Atomic Symbol Atomic
(complete)
Number
11
Protons
Neutrons
Electrons
Mass Number
Average
Atomic Mass
of element
B+3
5
5
6
2
11
10.811
Na+
11
11
13
10
24
22.989
31
31
34
31
65
69.72
Y
39
39
50
39
89
88.9056
Cu+2
29
29
35
27
64
63.546
100
Tc
43
43
57
43
100
98
207
Pb
82
82
125
82
207
207.2
Yb
70
70
102
70
172
173.04
Ac
89
89
136
89
225
227
Mo
42
42
53
42
95
95.94
81
81
125
78
206
204.383
100
100
159
100
259
257
No
102
102
159
102
261
259
Yb-1
70
70
102
71
172
173.04
106
106
159
106
265
263
24
65
Ga
89
64
172
225
95
206
Tl+3
259
Fm
261
172
265
Sg