Name _________________________
Date _______________
Chemistry 1-2 Enriched
6th Hour
Chapter 3 Study Guide
Vocabulary:
Section 1:
 law of conservation of mass
 law of definite proportions
 law of multiple proportions
 Dalton’s atomic theory
Section 2:
 atom
 cathode ray tube
 plum pudding model
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Section 3:
atomic number
isotope
nuclide
mass number
hyphen notation
nuclear symbol
unified atomic mass unit
average atomic mass
mole
Avogadro’s number
molar mass
Section 1:
1. Describe the law of conservation of mass, law of definite proportions, and law of multiple proportions.
2. What were the five parts of Dalton’s atomic theory? Which parts were proven to be incorrect and why?
Section 2:
3. Describe the contribution to the development of the model of the atom by the following scientists.
 Democritus
 John Dalton
 J. J. Thomson
 Ernest Rutherford  James Chadwick
4. Describe the experiments that lead to the discovery of the electron, atomic nucleus (proton), and neutron.
Section 3:
5. Describe a given isotope in terms of the number of protons, electrons, and neutrons, using the hyphen notation, or
using the nuclear symbol. (Practice A, Identifying Isotopes, Study Guide)
6. Determine the average atomic mass when given the atomic masses of the naturally occurring isotopes and their
percent natural abundance. (Identifying Isotopes, Study Guide)
7. Convert an amount of an element in moles to its mass in grams, and vice-versa. (Practice B, Practice C, Study Guide)
8. Convert an amount of element in moles to the number of atoms of that element, and vice-versa. (Practice D, Study
Guide).
9. Convert a number of atoms of an element to the mass in grams of that element, and vice-versa. (Practice E, Study
Guide).
Name _________________________
Date _______________
Chemistry 1-2 Enriched
6th Hour
Chapter 3 Study Guide
5. Complete the table below:
Hyphen Notation
Nuclear Symbol
Number of Protons
Number of Electrons
Number of Neutrons
sodium-23
11
11
12
copper-64
29
29
35
silver-108
47
47
61
calcium-40
20
20
20
iron-56
26
26
30
6. Determine the average atomic mass for each of the elements in the table.
Isotope
Atomic Mass
(u)
Percent Natural
Abundance (%)
Weighted Mass
(u)
Potassium-39
38.964
93.258
36.337
Potassium-40
39.964
0.012
0.005
Potassium-41
40.962
6.730
2.757
Iron-54
53.940
5.845
3.153
Iron-56
55.935
91.754
51.323
Average Atomic Mass
(u)
39.10
55.85
Iron-57
56.935
2.119
1.206
Iron-58
57.933
0.282
0.163
Name _________________________
Date _______________
Chemistry 1-2 Enriched
6th Hour
Chapter 3 Study Guide
7. Perform the following calculations.
a. What is mass in grams of 3.6 mol of the element carbon, C?
3.6 mol C
×
12.01 g C
×
32.06 g S
×
1 mol Cu
×
1 mol Li
=
43 g C
=
23.5 g S
=
0.0507 mol Cu
1 mol C
b. What is the mass in grams of 0.733 mol of the element Sulfur, S?
0.733 mol S
1 mol S
c. How many moles of copper, Cu, are in 3.22 g of copper?
3.22 g Cu
63.55 g Cu
d. How many moles of lithium, Li, are in 2.72 × 10-4 g of lithium?
2.72 × 10-4 g Li
=
3.95 × 10-5 mol Li
6.94 g Li
8. Preform the following calculations:
a. How many moles of carbon, C, are in 2.25 × 1022 atoms of carbon?
2.25 × 1022 atoms C
0.0374 mol C
C
× 6.022 ×110mol atoms
=
C
23
b. How many moles of oxygen, O, are in 2 000 000 atoms of oxygen?
2 000 000 atoms O
1 mol O
3.3 × 10-18 mol O
× 6.022 × 10
23
=
atoms O
c. How many atoms of sodium, Na, are in 3.80 mol of sodium?
3.80 mol Na
×
6.022 × 1023 atoms Na
1 mol Na
=
2.29 × 1024 atoms Na
9. Preform the following calculations:
10. What is the mass in grams of 5.0 × 109 atoms of neon, Ne?
5.0 × 109 atoms Ne
1 mol Ne
× 6.022 × 10
23
×
20.18 g Ne
atoms Ne
1 mol Ne
a. How many atoms of carbon, C, are in 0.020 g of carbon?
0.020 g C
×
1 mol C
×
6.022 × 1023 atoms C
=
=
1.7 × 10-13 g Ne
1.0 × 1021 atoms C
12.01 g C
1 mol C
b. What mass of silver, Ag, contains the same number of atoms as 10.0 g of boron, B?
10.0 g B
1 mol B
107.87 g Ag
99.8 g AG
10.81 g B
1 mol Ag
Since a mole is a definite number, 1 mole of one element has the exact same number of atoms as 1 mole of
another element. Therefore, we don’t need to convert from moles to atoms and then back.
10.0 g of boron has the same number of atoms as 99.8 g of silver.