Popcorn Energy Flow STEM Lab

Introduction:

In this lab you will create a model of energy flow through FOUR TROPHIC LEVELS of an ecological system.  You will use popcorn and various containers to represent energy flow through each trophic level. (There are  is NOT just one correct way model this.)  You will need paper and a calculator. You will practice using the metric system and calculating percentages.  You will then design a Google Slides presentation  and conclude the lab by teaching your class about energy flow in ecosystems.

Materials:

·                         One bag of popcorn per group.  All of this popcorn must be included on the bottom of your                    energy pyramid (1st Trophic Level)

·                        A variety of containers to represent trophic levels 

                One large plastic bag

               A piece of manilla tagboard to be used as a scoop/funnel

·                         Electronic balances and triple beam balances to calculate the amount of energy proceeding from one level to the next. (Remember, you need to mass only the energy and not the container you have on the balance, so subtract the mass of the container.)

·                          Broom and dustpan

·                          Chlorox Wipes (the waste energy gets all over the lab tables and leaves a greasy residue)

Directions:

1. Work in groups of about 4.

2. Read the section on page 77 of your textbook titled, "Pyramids of Energy."

3. Obtain 1 bag of popcorn from the Energy Supply area. Be sure to note special information on the bag (i.e. mass or volume).  This information may prove useful when you need to perform calculations. DO NOT THROW THE BAG AWAY!

4. Select containers from the materials at the Trophic Level Building Supply Store. You will use these to build a model of energy flow. 

5. Work to create a model of energy flow using your materials. You will write up your procedure such that another scientist could replicate your model. This means each step needs to be justified and explained thoroughly.

6. Special hint---remember only 10% of energy that enters a system makes it to the next trophic level. You need to be able to quantify the amount of energy that leaves a system as waste and the amount that makes it to the next trophic level. This is where the balance and calculator come in.  Include these calculations in your presentation.

7. When you are satisfied with your model, you will show create a 6 to 7 slide Google Slides presentation showing your procedure and results. Take photos with your phone to use in your presentation.   These photos should document your procedure.  Share your presentation with a few group members and nkeller@penncrest.org.

8. Each group will give their presentation on Friday.  You will explain your model to the class as you click through the presentation. 

9. While you are giving your presentation, include the following information:

               In the model, energy is represented by ____ and trophic levels are represented by ____.

               Describe the steps you used to represent energy flow.

              Identify the  types of organisms found at each level of the Pyramid of Energy

              Explain how you calculated the amount of energy lost between trophic levels.  Show your calculations of the amount of energy you began with, as well as the amount lost at each level and passed on at each level. 

              Explain where the missing energy goes.

              Explain why there are very rarely more than 4 levels in an Energy Pyramid.

              Explain why you think you had to do this lab. 

10. Eat your popcorn or throw it away! 

Adapted from a lab by Dr. A Scott, Athens Academy, Athens, GA