Modelling the Scientific Method with Glow Sticks

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.