Have you ever thought about the ways we, as chemistry teachers, talk about the concept of energy? Think about all the different terms we use when we talk about the role of energy in our curriculum: endothermic, exothermic, heat, specific heat, heat capacity, enthalpy, temperature, kinetic and potential – just to name a few. To further complicate matters, our physics and biology colleagues also talk about energy, and they bring their own set of terms and conditions to the conversation. Have you ever considered how the use of this disjointed vocabulary impacts how students think about energy?
One of my goals this year was to try and present a more accurate and consistent description of energy to my students, and to unify the definition between disciplines. I felt it was important for my students to understand that energy is energy. There are not different kinds of energy. The energy they learn about in biology is the same energy we talk about in chemistry and the same energy they study in physics. Students should not need to know three different definitions of energy for three different classes. I sat down with the teachers in my department and we drafted a definition of energy we each felt comfortable with using consistently in our classes. The definition we agreed on was, “energy is a conserved, substance-like quantity that can be transferred and has the ability to cause change”.
I challenge you to ask your students to define energy in their own words. Walk down the hall and ask students in a biology, physics, or earth science classroom to do the same. Do you think the definitions would be consistent?
The Modeling Curriculum does a nice job of providing analogies to students to help them understand the concepts of energy and energy transfer. Modelers use a tool called “energy bar charts” to help our students understand energy changes in a system. In my next article I will go into more detail on energy bar charts and how you can use them in your classroom.
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Comments 4
I've faced similar difficulty
I've faced similar difficulty with the idea of energy and the making and breaking of bonds between chemistry and biology. I found the clip here https://www.youtube.com/watch?v=uFQdcKJUijQ&feature=youtu.be#aid=P-pv7L4... ( just cut and paste) and forward to 20:35 - 22:00. This is described very easily here and will use this to get a good discussion going regarding activation energy and I like asking them to develop their own definition of energy.
The dreaded "high energy phosphate bond"
Doug,
I fought this battle too. The bio teachers I work with understood my concern with the phrase "breaking of the high energy phosphate bond releases energy". The way many textbooks describe photosynthesis contributes to the persistent misconception that bond breaking is exothermic. I shared this reference with my department to demonstrate the importance unifying our treatment of energy between disciplines.
Exothermic Bond Breaking: A Persistent Misconception William C. Galley J. Chem. Educ., 2004, 81 (4), p 523 Thanks for the video! I'll check it out!Energy Bar Charts?
Erica,
Thanks for this post. We had a bit of a discussion about this topic over the weekend as a department and hadn't thought of coming up with one departmental definition. One problem we face is our students (in grades 11 and 12) are in the IB curriculum. That means they have to know the definition as required by their subject. There are certainly differences between these subject areas.
I really look forward to learning about Energy Bar Charts.
Thanks.
Lowell
Energy Bar chart example
I am also the physics teacher at my school, and because of this, I use energy bar charts to show the interaction of kinetic, potential and work energies (my source is http://www.physicsclassroom.com/getattachment/curriculum/energy/energy6.pdf). I would be interested in seeing if this model can be adapted to energy in chemistry.