Name:_________________________________Hour:_________
Date: ________________________________
Modelling the Scientific Method
As we have discussed the scientific method is a process that is pivotal to obtain results and
drawing conclusions. It is the universal language for scientists and has been used for many years.
Today we are going to work through an experiment. As you and your group complete this
experiment notice the steps involved, specificity, variables, data collection, as well as other
aspects because you will be asked to create your own experiment in the very near future!
Background Information: What makes a glow stick work?
Light is generated by a chemical reaction called “chemiluminescence”. Typical glow sticks as
chemical reactants using a hydrogen peroxide solution (which is called the "activator"), a
solution of phenyl oxalate ester and a fluorescent dye (which makes the color). The activator is
stored in a thin glass capsule. When the glass capsule is broken (by flexing a glow stick) the
activator is released, and mixing the components (shaking the glow stick) initiates the reaction.
Depending on components used, the chemical reaction can last (glow sticks can glow) from a
few minutes to many hours.
Step 1: Problem: Temperature does affect the reaction of the glow stick.
Step 2: Hypothesis
Using the observations you made as well as any prior knowledge please create a hypothesis to
answer the following question: Which glow stick will burn the brightest-the one in hot water,
cold water, or water at room temperature?
REMEMBER: Any hypothesis is written as an “if-then” statement.
1. Write your hypothesis on your lab report:
Step 3: Procedure:
1. Obtain 3 glow sticks.
2. Make your observations about the glow sticks and record this information. (record the
information in the data section of your lab).
3. Obtain 3 beakers (or containers) of water. One beaker must contain hot water, the
second beaker room temperature water and the third will contain cold water.
4. Activate your glow sticks.
5. Record any observations.
6. Place one glow stick in each beaker.
7. Keep the glow stick in the container for 10 minutes.
8. At the end of ten (10) minutes record the brightness of each of the glow sticks using
the follow measurement. Dull , lights up , and burns bright
9. Clean up your lab station.
10. Organize your data.
Step 4: Data Collection
Step 5: Analysis: Discuss the data. Be sure to refer to the data tables and graphs.
Step 6: Conclusion: Accept or Reject the hypothesis
Name: _____________________________________
Observing Glow Sticks
Date: ___________________________ Hour: _____
Hypothesis:
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Data Collection
In order to draw conclusions a scientist must record data. This data must be easy to understand
for an “outsider.” Therefore it must be clear, organized, and fairly concise. Below please write
the data table that our class decided on.
a. Will we be making a Qualitative data table or a quantitative data table? How do you
know? ________________________________________________________________
Observations
Please write three observations of the glow sticks in the front of the room.
1.
2.
3.
Data Table:
-Create a data graph from the information in your data table #2 (attach it)
Analysis
In the space below write an analysis based on the data your group recorded. This conclusion
should restate the hypothesis as well as use data as support.
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Conclusion
In the space below write a conclusion based on the analysis. This conclusion should restate the
hypothesis as well as use data as support.
______________________________________________________________________________
______________________________________________________________________________
Questions:
1. Please list two sources of possible human error.
a.
b.
2. What was the control?
3. What was the independent variable?
4. What was the dependent variable?
5. Why would retesting this experiment be valuable?
6. Describe the difference between quantitative and qualitative data.
7. A student planted bean seeds in 3 identical pots. She labeled the pots A, B, and C and she
gave all of them 125mL of water. She place one pot in a sunny window, one under
normal classroom lights, and one in a dark room. All of the plants were kept at the same
temperature. At the end of 30 days she measured the height of the plants and got the
following results.
Plant
Plant A
Plant B
Plant C
a.
Lighting
Window Light
Room Lighting
Dark Closet
Growth in cm
30.0 cm
21.0 cm
0.0 cm
Identify the independent variable for the experiment above: ____________________
b. Identify the dependent variable for the experiment above: ______________________
c. List three constants for the experiment described above.
i.
ii.
iii.