Unit X 2Review
Unit
Review
Unit 2 Review
Name
Vocabulary
Fill in the blank with the term that best completes the sentence.
1 A(n) measurement
using a standard unit.
is a determination of the dimensions of something
2 The speed of light is approximately 300,000,000 m/s. When scientists write that
very large number as 3 × 108 m/s, they are using scientific notation .
7.2C
3 The system that standardizes measurements in order to allow people around the
world to compare results of experiments is called the International System
. of Units
4 The sum of all values in a data set divided by the total number of values in the set
is the mean
of the data.
7.3B
5 A(n) model
is a pattern, plan, representation, or description
designed to show the structure or workings of an object, system, or concept.
Key Concepts
Choose the letter of the best answer.
7.2C, 7.2D
6 Neil drops a ball from four different heights. The table shows how long it took
each ball to reach the ground.
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Time to drop from various heights
Trial
?
A
B
C
D
5
25
45
80
Time
(s)
1
2
3
4
Which of the following could be a correct label for the second column?
A Speed (m/s)
C Height (m)
B Mass (g)
D Length of drop
Unit 2 Review
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Unit 2 Review continued
7.2C
7 Scientists use which one of the following units to measure mass?
A pound
C kilogram
B meter
D ounce
8 The image below shows four measurements (small dots) and an actual value
(large center).
How are these measurements
best described in terms of accuracy and precision?
6-8-K_CNLAEAG593500_3A
(Hint: Step 1. Recall the definition of accuracy. Are the dots near or far from the
actual value? What does that indicate? Step 2. Recall the definition of precision.
Are the dots near or far from each other? What does that indicate?)
A The measurements are accurate and precise.
B The measurements are accurate but not precise.
C The measurements are precise but not accurate.
D The measurements are neither accurate nor precise.
7.2C, 7.4A
A test tube
C electron microscope
B hot plate
D yardstick
10 How should scientists express very large numbers when reporting data?
A in scientific notation
C as a fraction
B to the tenth decimal point
D in inches
98
Unit 2 Measurement and Data
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9 Which is a tool that scientists would be least likely to use in a lab?
Unit 2 Review
Name
7.3B
11 Marvin is studying how joints move. He uses the hinge shown below to
represent how the elbow moves.
Which of these phrases best describes what Marvin is doing?
A collecting data
C simulating an elbow
B observing nature
D taking measurements
7.3B, 7.3C
12 A scientist used a model to predict the path of a hurricane. The hurricane
followed a similar path but did not follow the exact path that was predicted.
How does this example demonstrate a limitation of models? (Hint: Step 1. Recall
the definition of model. Step 2. Consider what models can and cannot do. Step
3. Compare the advantages and limitations of models to the answer choices.)
A Models cannot be used to predict things.
B Models can be used to predict weather events before the event occurs.
C Models cannot account for how every factor may suddenly change.
D Models can only be used to show physical structures, not events such as
hurricanes.
Gridded Response
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Write the answer to the question, then fill in the corresponding circle.
13 Earth has a mass of about 5,970,000,000,000,000,000,000,000
kilograms. What is the number written before the power of ten when
this number is written in scientific notation?
5 . 9 7
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Unit 2 Review
99
Unit 2 Review continued
Critical Thinking
Answer the following questions in the space provided.
7.2C, 7.2D, 7.2E
14 Every 10 days, a scientist measured the height of a tomato plant growing in
full sun and a tomato plant growing in part shade. The results are shown in
the table below.
Plant Growth
Conditions
full sun
part shade
Initial height
(cm)
20
20
Height after
10 days (cm)
24
22
Height after
20 days (cm)
27
23
Height after
30 days (cm)
31
25
a. What was the height of each plant after 30 days?
31 cm for the plant in full sun and 25 cm for the plant in part shade
b. What can be concluded about the growth rate of tomato plants grown in full
sun compared to those grown in part shade?
tomato plants grown in full sun grow faster than tomato plants grown in part
shade
Connect
ESSENTIAL QUESTIONS
Lessons 1 and 2
Answer the following question in the space provided.
15 You want to determine the average time it takes you to get to school. If you
measured travel time every day for a week, describe what tool you would use,
how you could graph your daily data, and how you could calculate average time.
a scatter plot shows where the data points fall on a grid. If the data points
But if the data points are spread widely across the scatter plot, the data are
not precise.
100 Unit 2 Measurement and Data
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fall on a grid. If the data points are close to each other, the data are precise.