PENNY LAB
Purpose: To determine how many drops of water fit on one side of a penny.
Hypothesis: (Use an if-then-because statement for your hypothesis)
If soap solution is poured on the penny, then less water will fit on one side of a penny because of soap solution, water will drop on the towel.
Materials: (List all the materials used in the experiment)
Pennies, water, soap solution, paper towel, eye droper, tweezers.
Procedure:
Part A: Perform a CONTROL test for comparison with later results.
Step 1: Rinse a penny in tap water and dry completely.
Step 2: Place the penny on paper towel.
Step 3: Use an eye dropper to place drops of WATER on the penny (one at a time) until ANY amount of water runs over the edge of the penny.
Step 4: Record the number of drops for that trial in the table.
Repeat Steps 1 – 4 three more times before calculating your average.
| Number of drops
TRIAL 1 |
Number of drops
TRIAL 2 |
Number of drops
TRIAL 3 |
Number of drops
TRIAL 4 |
AVERAGE Number of drops
|
| 31
|
26 | 32 | 17 | 27 |
Part B: Perform tests with the TESTING LIQUID.
Step 1: Start with a “clean” penny. Rinse the penny in tap water and dry completely. Be sure to remove as much residue as possible – without using soap!
Step 2: Hold the penny with the tweezers provided, then dip it into the TESTING LIQUID. Allow extra liquid
to drip off the penny into the container before proceeding to the next step.
Step 3: Place penny on dry spot on a paper towel. Place drops of WATER on the penny (one at a time) until ANY amount of water runs over the edge of the penny.
Step 4: Record your observations and the number of drops for that trial in the table.
Repeat Steps 1 – 4 three more times before calculating the average.
| TRIAL 1 | TRIAL 2 | TRIAL 3 | TRIAL 4 | AVERAGE |
| 0
|
6 | 7 | 7 | 5 |
Observations:
| Part One: Labelled Diagram of observations:
|
Part Two: Labelled Diagram of observations:
|
| Description: We drop the water on the penny by using eye droper. Our average number of drops is 27. | Description: We drop the water on the penny that cover with soap solution by using eye droper. Our average number of drops is 5.
|
Results:
| Group # | Average Number of water Drops on the Control Penny | Average Number of Drops on the
Penny submersed in the soap solution |
| Group One
|
27 | 5 |
| Group Two
|
22 | 5 |
| Group Three
|
33 | 6 |
| Group Four
|
20 | 5 |
| Group Five
|
34 | 8 |
| Class Average:
|
27 | 6 |
Conclusion:
This experiment investigated….
In this experiment, soap solution could improve number of water drops on the penny or soap solution could not improve.
In order to study the problem …
There are two parts to this experiment. One part is just to drop the water on the penny. Other part is to drop the water on the penny that is covered with soap solution.
Results showed…
With the penny that is covered with soap solution, the number of water drops on the penny is decreased.
This proved the hypothesis that if… then…was (supported/negated) because… Explain if/how cohesion and surface tension came into play for this experiment. How do your results compare to the other groups in your class? Provide at least 2 possible reasons for any similarities and differences you identified.
Hypothesis is supported because soap solution breaks down the surface tension so less water fit on surface of a penny.
It is similar but not exactly same, because when drop the water by using eye dropper, amount of water dropped on the penny may differ due to the strength used to squeeze the eye dropper. Other reason is difference of the position of water drop.
To extend this experiment (explain what could be done)…
To extend this experiment another type of soap solution can be used.
Finally, if the experiment was repeated, some changes to improve the experimental design could be…adjusting the eye dropper so that the same amount of water drops every time.
****REMEMBER TO AVOID THE USE OF PERSONAL PRONOUNS****
Post 2 photos (penny with water only and penny with testing liquid) and your conclusion to your edublog site. Tag “Durand_PennyLab2019”