The bubble gum experiment
SNC 1P - Learning Scientific Method
DAY 1
Imagine that you made the best chocolate cake ever! Everyone who tried a piece loved it and
begged you for the recipe. You would have to write down everything you did, from the ingredients, to
the steps, even to the pots and pans you used. If you left anything out, anything at all, then other
people might not be able to make your cake. Lab reports work like recipes. Steps are written out in
great detail so that someone else, working thousands of miles away can “make the cake.”
Lab reports follow a strict format that all researchers use, that way experiments can be
repeated. You may recall from previous science classes that the scientific method is used when
writing lab reports. The scientific method attempts to identify causes and effects of a specific
experiment in a systematic manner.
Lab reports always start with a question. Something has to catch your interest, enough so that
you want to learn more about it. Let's say that you want to know if the type of brand of gum effects the
size of the bubbles it makes.
Question: Does the brand of gum effect the size of the bubble blown?
The question is often phrased as a purpose. This is where you state what you are trying to identify. It
must be stated as a cause and effect relationship.
Purpose:
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Now you must design an experiment to determine if you are correct. You will need consider what else
will effect the size of the bubble.
Other than brand, what variables can effect the size of a bubble? ____________________________
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Remember, we only want to see if the brand makes a difference. What do we need to do with the
other factors? _________________________________________________________
These are called the Controlled Variables.
Determining the designated bubble maker:
Table 1. Bubble sizes for each member of the group.
Trial #
Bubble size (cm) for
member #1
Bubble size (cm) for
member #2
Bubble size (cm) for
member #3
1
2
3
4
5
Average
DAY 2
By isolating causes, one can clearly identify a factor that has an effect on some observation. It
is based on three main variables: the independent variable, the dependent variable and the
controlled variable.
Controlled variables:
Independent variable:
Dependent variable:
In the bubble gum experiment:
3 controlled variables are: ________________________________________________________
The independent variable is: ________________________________________________________
The dependent variable is: ________________________________________________________
Now you must design an experiment to determine if you are correct. Decide what equipment and
materials you will need and list them. They can be in the form of a bulleted list.
Materials:
_________________
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_________________
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Now you must list the steps that you will take, also known as the procedure.
Methods:
1. Using the same person, blow five bubbles for each brand.
2. Measure in cm the size of each bubble and record.
Observations:
Observations can be measured using either qualitative or quantitative.
Quantitative observations:
For example:
Qualitative observations:
For example:
Quantitative Observations:
Table 2. Bubble sizes for each type of gum.
Trial #
Bubble size (cm) for
_________________
Bubble size (cm) for
___________________
Bubble size (cm) for
________________
1
2
3
4
5
Average
Qualitative Observations:
You should write a description of any notable observations (how the bubble bursts, stickiness…)
Results Summary:
In this section you will summarize your findings using quantitative and qualitative statements.
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After your observation, it is time for you to attempt to explain why your results occurred. This is the
discussion. Using the internet, find out what causes the gum to bubble out and make connections to
the experiment conducted in class. For example:
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What causes the gum to swell out?
Why could different brands effect the bubble size?
If your results do not match the internet research, what might have gone wrong?
Discussion:
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