Experiments
Experiments
Objectives
In this unit, students will learn the components of a scientific experiment, how to accurately design and perform an experiment, and how to analyze results taken from the experiment. Students will:
- form a hypothesis.
- identify controls and variables in experiments.
- make observations.
- create a graph.
- analyze data.
- draw conclusions.
- identify bias and flaws in the experiment.
Essential Questions
Related Unit and Lesson Plans
Related Materials & Resources
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Materials haven't been entered into the unit plan.Formative Assessment
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Multiple-Choice Items:
1. Which type of error involves the experimenter making a mistake?
A
Systematic
B
Automatic
C
Human
D
Random
2. Read the following experiment and determine the dependent variable.
An experiment was conducted that involved measuring the heart rate of a patient 20 minutes before and after consuming 32 oz of the same caffeinated beverage. 100 female patients were tested at the same time each day.
A
Heart rate
B
Caffeine
C
Number of patients
D
Time of day
3. Which is an example of an observation about an earthworm?
A
The earthworm likes warm soil.
B
The earthworm is 95 centimeters long.
C
The earthworm is good at crawling.
D
The earthworm prefers the color brown.
4. Refer to the line equation below and determine the y-intercept:
y = 7x + 4
A
7
B
7x
C
7x + 4
D
4
5. Which statement best defines slope?
A
Steepness of a line
B
A given set of coordinates
C
The point at which the line crosses the x-axis
D
The point at which the line crosses the y-axis
6. Read the following experiment and determine the control.
A test was conducted that involved looking for the presence of an acid among a group of unknown liquids. The test involves using blue litmus paper. Blue litmus paper turns red in the presence of an acid, but stays blue in the presence of a base.
A
Testing the unknown liquids with red litmus paper
B
Testing the unknown liquids with blue litmus paper
C
Testing the blue litmus paper with a liquid known to be acidic
D
Testing the blue litmus paper with distilled water (neither an acid nor a base)
7. Which hypothesis best represents the experiment below?
A student wants to make rock candy and is interested in determining if heating the water makes the sugar dissolves faster.
A
If the water is heated, then more sugar can be dissolved.
B
If you add more sugar, then the rock candy will be sweeter.
C
If you add more sugar, then the rock candy will be harder.
D
If the water is heated, then the sugar will dissolve at a faster rate.
8. Which statement best describes an inference?
A
A mistake by the experimenter
B
A statement of fact, based on the five senses
C
An estimation of an unknown value based on given data
D
An opinion based on prior knowledge or experience
9. Which statement best describes the relationship between the independent and dependent variables?
A
Dependent variables change in response to changes in the independent variables.
B
Dependent variables and independent variables both change without the influence of one another.
C
Independent variables change and dependent variables always remain constant.
D
Independent variables change in response to changes in the dependent variables.
Multiple-Choice Answer Key:
1. C
2. A
3. B
4. D
5. A
6. C
7. D
8. D
9. A
Short-Answer Items:
10. As you begin determining the mass of a penny, you notice that the electronic scale reads 0.45g, even though there is nothing on it. What type of error is this, systematic, human, or random? Explain.
11. Place the following steps of an experiment in order.
- Record/analyze data.
- Communicate results.
- Make a hypothesis.
- Make a conclusion.
- State the problem.
- Conduct the experiment.
Short-Answer Key and Scoring Rubric:
10. As you begin determining the mass of a penny, you notice that the electronic scale reads 0.45g, even though there is nothing on it. What type of error is this: systematic or human? Explain.
Points
Description
2
- Student identifies the error as a systematic error.
- Student appropriately explains that a systematic error is an error inherent in the experimental set up which causes the results to be skewed in the same direction every time. In this particular case, failing to zero out or tare the scale before measurement will cause the same type of error throughout the experiment whenever the scale is used.
1
- Student fails to correctly identify the type of error or fails to explain his/her answer.
0
- Student demonstrates lack of understanding or does not attempt to complete the assessment.
11. Place the following steps of an experiment in order.
- Record/analyze data.
- Communicate results.
- Make a hypothesis.
- Make a conclusion.
- State the problem.
- Conduct the experiment.
Answer KEY:
1.State the problem.
2.Make a hypothesis.
3.Conduct the experiment.
4.Record/analyze data.
5.Make a conclusion.
6.Communicate results
Performance Assessment:
Using the data provided to you in the table below:
- Create a scatter plot.
- Label both axes:
o Distance (independent variable)
o Time (dependent variable)
- Create an appropriate title.
- Draw a line of best fit.
- Use slope-intercept form to determine the equation of the line (y = mx + b). Show all of your work.
Distance (m)
Time (s)
0
0
25
1
50
2
75
3
100
4
125
5
Performance Assessment Scoring Rubric:
Points
Description
5
Student completes all five of the requirements:
- Scatter plots are clearly marked on the graph.
- Axes are labeled correctly: x-axis as Distance (m); y-axis as Time (s).
- Graph title includes the independent and dependent variables and is appropriately located.
- Line of best fit goes through all six scatter plots.
- Slope of the line is correct and all work is shown:
4
Student completes four of the requirements.
3
Student completes three of the requirements.
2
Student completes two of the requirements.
1
Student completes one of the requirements.
0
Student demonstrates lack of understanding or does not attempt to complete the assessment.
DRAFT 05/12/2011
