Curriculum Initiatives >>
Chemical Reaction Vehicles A STEM project takes off in fifth-grade classrooms. The classroom is abuzz. Students surround the test track, craning their necks for a better view. An engineering team works together to load chemicals, add water with a syringe, quickly fix a cork into the bottle, and position their chemi- cal reaction vehicle against the wall. They step back and crouch low as pressure builds in the chamber. Some children cover their ears in anticipation. One member of the team lies down on the oor, peering through her goggles to determine if there is a leak. Suddenly, a loud pop explodes and the car is propelled forward while children scream in surprise or cheer the success of their classmates. As the boy and girl measure the distance their vehicle traveled, they discuss how to adjust the amount of chemicals to improve its performance, and a new team prepares for the next test. The joy and excitement about science and engineering is au- dible throughout the afternoon. The fifth-grade students at Hong Kong International School have been learning about the structures and properties of matter for many years, but two years ago the teachers added an engineering design challenge to provide them with the opportunity to apply their understanding of how matter behaves and changes to solve a problem. The chemical reaction vehicle design challenge was the culminating experience in a unit called “Structures and Properties of Matter.” During this unit, students explored basic properties of matter, various physical changes of matter, and indicators of chemical changes. In the preface of the book The Essential Engineer: Why Science Alone Will Not Solve Our Global Problems, Henry Petroski (2010, p. IX), “... seeks to illuminate the differences between science and engineering and thereby clarify their respective roles in the worlds of thought and action, of knowing and doing.” Petroski argues that it is the interaction of both science and engineering that is necessary to solve critical global issues including climate change and clean, renewable energy sources. Engineering is, then, the application of what we know about science. The Next Generation Science Standards (NGSS) echo Petroski’s ideas. A Framework for K–12 Science Education (NRC 2012) notes that students deepen their understanding of science by applying their knowledge to engineering and technology to solve practical problems. Students design their own vehicles to test.
A student records data about his vehicle. 16 EARCOS Triannual Journal
By Wendy Smith and Jesse Meyer
Both positions converge on the intention of integrating technology and engineering into the science curriculum so students feel empowered to use what they learn in their everyday lives.
Introducing the Challenge The engineering design challenge presented to students required them to use their “...knowledge of science to help design and build a vehicle that is powered solely by a chemical reaction.” Once the project was introduced, the students shared their understandings of the challenge and formulated questions to clarify misunderstandings. Some questions included: • What materials can we use? • How do we make a chemical reaction? • Can we use a toy car that we have at home? • How much time do we have to do the project? • Can we pick our partners? Next, the teachers presented the criteria and constraints in order to answer the students’ questions and to provide clarification (Figure 1; See NSTA Connection for project introduction). FIGURE 1. Project criteria and constraints. Criteria Vehicle must travel at least 1 m. Constraints • Vehicle must not exceed 30cm. • Vehiclemustbeconstructed using available materials (no toy cars). • Chemical reaction must occur from combining the substances and water available in the classroom. • Once the chamber for the reaction is chosen, no changes can be made to that part of the design. The decision regarding how partnerships were created was left up to individual teachers. Some chose to assign partner groups, while others let the students decide. The timeline for the project was also determined by each classroom teacher, with some preferring to do the project over three to four days with two to three hours of project time each day, while others completed the project over two weeks with approximately one hour of project time each day. Parts 1 and 2, described below, take approximately equal amounts of time. While all the students at our school had experience in previous grades with engineering design challenges, the teachers felt that a quick refresher on the process prior to starting the project would benefit students. Crash Course Kids, a YouTube channel focusing on elementary science, has a series of short, engaging videos on an engineering design process. Teachers shared the episode, “The Engineering Process: Crash Course Kids #12.2.” Students discussed the video and compared
