Name _________________________
Date _______________
Chemistry 1-2
_____Hour
Unit 2 Review
Vocabulary:
Chapter 3
 law of conservation of mass
 law of definite proportions
 law of multiple proportions
 Dalton’s atomic theory
 atom
 atomic number
 isotope
 mass number
 hyphen notation
 nuclear symbol
 unified atomic mass unit
 average atomic mass
Chapter 5
 periodic law
 periodic table
 period
 group
 alkali metals
 alkaline earth metals
 transition metals
 metalloids
 nonmetals
 halogens
 noble gases
 lanthanides
 actinides
Chapter 3
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?
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
4. Describe a given isotope in terms of the number of protons, electrons, and neutrons, using the hyphen notation, or
using the nuclear symbol.
5. Compare how isotopes contribute to the average atomic mass of an element when given the atomic masses of the
naturally occurring isotopes and their percent natural abundance.
6. Describe the contribution to the development of the periodic table of elements by the following scientists.
 Dmitri Mendeleev
 Henry Moseley
7. Identify key properties of the chemical families of the periodic table. Use these properties to place an element in the
correct family.
 alkali metals
 metalloids
 Noble gases
 alkaline earth metals
 non-metals
 lanthanides
 transition metals
 halogens
 actinides
Name _________________________
Date _______________
Unit 2 Review
Chemistry 1-2
_____Hour
Name _________________________
Date _______________
Chemistry 1-2
_____Hour
Unit 2 Review
8. Complete the table below:
Hyphen Notation
Nuclear Symbol
Number of Protons
Number of Electrons
Number of Neutrons
sodium-23
64
29Cu
silver-108
20
20
26
30
9. Answer the questions regarding the average atomic mass of each of element using the table below.
Isotope
Atomic Mass
(u)
Percent Natural Abundance
(%)
Potassium-39
38.964
93.258
Potassium-40
39.964
0.012
Potassium-41
40.962
6.730
Iron-54
53.940
5.845
Iron-56
55.935
91.754
Average Atomic Mass
(u)
39.098
55.845
Iron-57
56.935
2.119
Iron-58
57.933
0.282
a. Which isotope of potassium contributes most to the average atomic mass of potassium? How do you know?
b. Which isotope of potassium contributes least to the average atomic mass of potassium? How do you know?
c. Which isotope of iron contributes most to the average atomic mass of iron? How do you know?
d. Which isotope of iron contributes least to the average atomic mass of iron? How do you know?