Roisin A. Macdonald
I teach seventh and eighth grade science at Betsy Ross Arts Magnet Middle School in New Haven. Betsy Ross is an inter-district middle school with students not only from New Haven but also from surrounding suburban towns. Being an inter-district magnet school has led to a diverse student population, the majority of which are living within New Haven City limits (i.e. approximately 25% within the school's neighborhood and 50% from other areas of New Haven); the remaining 25% are from suburban towns. As my school is an Arts Magnet School it makes sense that many of the students are creative and active, more so than normal. This attribute can be advantageous for me as teaching science through example and hands on activity are what I strive to do. My students, thus far, have done very well with interactive laboratory experiences and project based assessments. Whenever possible, I try and relate the content being taught to the student's everyday experiences.
The mere thought of science class frightens the average middle school student. There are, of course, the exceptions. It is more likely that even if a student finds science interesting, and therefore appealing at some level, they may not be willing to admit it. Throw the word chemistry into the mix and shivers run down their spines! The unit Sweet Twinkie, Brownies, Density and Sugar Chomping Yeast: A look at physical and chemical reactions in the kitchen enables me to present material regarding chemical and physical properties as well as basic chemical reactions from the viewpoint of food and baking. Overall, I do not believe that students would associate food with chemistry since chemistry is a mysteriously hard subject that the average person can never comprehend. There must be some secret to discovering and understanding complex concepts of chemistry, isn't there? The answer, of course, is no. Chemistry is in action every time we take a bite of an apple, make toast, scramble eggs, pop open a can of soda; the examples are endless.
My unit is intended for a heterogeneous group of 20-25 seventh graders and will be initiated with a discussion of how chemistry is an important part of all our lives, every day we take part in an insurmountable number of chemical reactions. Making initial connections by having students discuss what their morning was like and how chemistry played an important role will be the goal of the first lesson. Before honing in on the intended food subject area we will activate prior knowledge of molecules and how they move dependant on the state of matter (class activity: Movin' Molecules). An introduction to chemical and physical properties is presented with the concluding portion of the lesson illustrating how mixing/melting ingredients are examples of physical changes while baking those mixed ingredients culminates a chemical change. Students explore the concept of density, determining the density of a Twinkie utilizing both the geometric and water displacement method for determining volume. As this lesson pertains to baked treats, the use of leavening agents used to make these treats light and fluffy is covered, we will review the four types of leavening agents. The culminating lesson of this unit allows students to examine the production of CO2 during the fermentation process of yeast feeding on sugar water.
