Penny Drops Lab
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Scientific Thinking Standard I: Understand the processes of scientific investigations and use inquiry and scientific ways of observing, experimenting, predicting, and validating to think critically.
Performance Objective: Students will justify predictions and conclusions based on data.
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Demonstration/Background Information: The teacher will review the concept of cohesion. Cohesion occurs when water molecules are attracted to other water molecules. The oxygen end of water has a negative charge and the hydrogen end has a positive charge. The hydrogens of one water molecule are attracted to the oxygen from other water molecules. This attractive force is what gives water its cohesive properties. The activity we are doing today will help you understand this process even better.
Activity: Students will perform an investigation where they will demonstrate cohesion using water and a penny.
Question: How many drops of water will a penny hold?
Hypothesis: I predict a penny will hold _______ drops of water.
Materials: 2 pennies, 2 eyedroppers and 2 small cups of water
Safety Precautions: No horseplay with water; clean up spills immediately to prevent accidents; report any incidents/accidents to the teacher
Procedure:
1. Work in pairs.
2. Make your prediction; if you can’t agree, make two predictions, as you will compare your results.
3. Gather materials.
4. Each team member may work simultaneously as long as each person stays focused on the activity.
5. Put the penny on a flat surface (Have the penny resting on a paper towel).
6. Count the number of drops until the water spills over the edge of the penny.
7. Record your data.
8. Repeat the steps for a total of 5 trials.
9. Take an average of your results.
10. Compare results with your team member.
Data Chart:
Scientific Thinking Standard I: Understand the processes of scientific investigations and use inquiry and scientific ways of observing, experimenting, predicting, and validating to think critically.
Performance Objective: Students will justify predictions and conclusions based on data.
_____________________________________________________________________________________________________________________________________
Demonstration/Background Information: The teacher will review the concept of cohesion. Cohesion occurs when water molecules are attracted to other water molecules. The oxygen end of water has a negative charge and the hydrogen end has a positive charge. The hydrogens of one water molecule are attracted to the oxygen from other water molecules. This attractive force is what gives water its cohesive properties. The activity we are doing today will help you understand this process even better.
Activity: Students will perform an investigation where they will demonstrate cohesion using water and a penny.
Question: How many drops of water will a penny hold?
Hypothesis: I predict a penny will hold _______ drops of water.
Materials: 2 pennies, 2 eyedroppers and 2 small cups of water
Safety Precautions: No horseplay with water; clean up spills immediately to prevent accidents; report any incidents/accidents to the teacher
Procedure:
1. Work in pairs.
2. Make your prediction; if you can’t agree, make two predictions, as you will compare your results.
3. Gather materials.
4. Each team member may work simultaneously as long as each person stays focused on the activity.
5. Put the penny on a flat surface (Have the penny resting on a paper towel).
6. Count the number of drops until the water spills over the edge of the penny.
7. Record your data.
8. Repeat the steps for a total of 5 trials.
9. Take an average of your results.
10. Compare results with your team member.
Data Chart:
Number
of Drops of Water held on a Penny |
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Name |
Trial 1 |
Trial 2 |
Trial 3 |
Trial 4 |
Trial 5 |
Average |
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Effective Questions: (Discuss with your teammate before answering the questions.)
1. Did you get the same data each time you performed the investigation? Why or why not?
___________________________________________________________________________________________________________________________________.
2. Compare your results with your partner and then with your other classmates. Did they get the same results as you? Why or why not?
___________________________________________________________________________________________________________________________________.
Analyze and Conclude:
1. Was your prediction correct? If yes, rewrite the statement to express this answer. If no, why?
___________________________________________________________________________________________________________________________________.
2. How could you make this activity more challenging? Think of 2-3 ways.
a. ___________________________________________________________________________.
b. ___________________________________________________________________________.
c. ___________________________________________________________________________.
(Trimpe, 1999)
1. Did you get the same data each time you performed the investigation? Why or why not?
___________________________________________________________________________________________________________________________________.
2. Compare your results with your partner and then with your other classmates. Did they get the same results as you? Why or why not?
___________________________________________________________________________________________________________________________________.
Analyze and Conclude:
1. Was your prediction correct? If yes, rewrite the statement to express this answer. If no, why?
___________________________________________________________________________________________________________________________________.
2. How could you make this activity more challenging? Think of 2-3 ways.
a. ___________________________________________________________________________.
b. ___________________________________________________________________________.
c. ___________________________________________________________________________.
(Trimpe, 1999)