Download 8th Grade Chapter 3 Study Guide

8th Grade Chapter 3 Study Guide
Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.
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1. When a substance burns, matter is destroyed. _________________________
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2. Elements on the far right of the periodic table are classified as nonmetals. _________________________
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3. Thompson's experiments led to the discovery of the neutron. _________________________
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4. The closer an electron is to the nucleus, the lower its energy. _________________________
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5. Every atom of the same element has the same atomic number. _________________________
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6. For an atom to be neutral, the number of protons must equal the number of neutrons.
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7. Matter always has mass. _________________________
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8. Pure substances are either elements or mixtures. _________________________
Multiple Choice
Identify the choice that best completes the statement or answers the question.
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9. Matter that has the same composition and properties throughout is called a(n) ____.
A. pure substance
C. atom
B. mixture
D. isotope
10. When two pure substances are combined so that each of the pure substances retains its own properties, the
result is a(n) ____.
A. compound
C. element
B. mixture
D. isotope
11. All ____ except mercury are solids at room temperature.
A. metalloids
C. metals
B. nonmetals
D. mixtures
12. How many atoms of calcium are in a unit of calcium phosphate whose formula is Ca3(PO4)2?
A. one
C. three
B. two
D. four
13. In general, nonmetals are ____.
A. good conductors of electricity
C. good conductors of heat
B. malleable and ductile
D. gases at room temperature
14. In general, metals are ____.
A. poor conductors of heat
C. poor conductors of electricity
B. brittle
D. good conductors of heat
15. When Rutherford performed his metal foil experiment, he was surprised that most of the alpha particles ____.
A. were deflected by the foil
C. were absorbed by the foil
B. bounced back from the foil
D. passed straight through the foil
16. Which of these statements about matter is NOT true?
A. During chemical changes, matter is destroyed.
B. Matter has mass and takes up space.
C. Matter can be divided into pure substances and mixtures.
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D. Matter is made up of atoms.
The millions of compounds that exist are made from approximately ____ elements.
A. 50
C. 118
B. 75
D. 150
Most of the mass of an atom is found in its ____.
A. nucleus
C. atomic number
B. electron cloud
D. mass number
Vegetable soup is an example of a ____.
A. homogeneous mixture
C. compound
B. heterogeneous mixture
D. pure substance
When someone stirs cocoa powder into hot water or hot milk, the cocoa changes from a ____.
A. homogeneous mixture into a compound
B. homogeneous mixture into a non-uniform mixture
C. compound into a heterogeneous mixture
D. heterogeneous mixture into a homogeneous mixture
A certain atom has 26 protons, 26 electrons, and 30 neutrons. It mass number is ____.
A. 26
C. 52
B. 30
D. 56
Which of the following CANNOT be classified as matter?
A. an odorless, colorless gas
C. alpha particles
B. the heat given off by a light bulb
D. an electron cloud
____ has mass and takes up space.
A. Thought
C. Air
B. Light
D. Emotion
Matching
Match the drawings in Figure 3-1 to the descriptions below.
Figure 3-1
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24.
25.
26.
27.
28.
element
mixture of two elements
compound
mixture of two compounds
mixture of a compound and element
Match each symbol or formula with the correct element or compound.
A. O2
C. CO
B. CO2
D. C
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29.
30.
31.
32.
carbon
oxygen
carbon monoxide
carbon dioxide
Short Answer
33. Except during World War II when steel pennies were made, pennies minted before 1984 were made entirely
of copper. Pennies made later have a core of zinc covered by a thin layer of copper. Nickels contain about
25% copper and 75% nickel. Classify each type of coin in terms of elements, compounds, homogeneous
mixtures, and heterogeneous mixtures.
34. Give four examples of properties of nonmetals that are exactly the opposite of properties of metals.
35. What did Rutherford expect to happen when he bombarded metal foil with alpha particles? How did his
results change the model of the atom?
36. Use the periodic table to complete the data in Table 3-1.
Properties of Selected Elements
Symbol
Name
Atomic number
Average Atomic
Mass
Fluorine
O
15
S
32.066
Table 3-1