Applying the Versatility of Chem Lab Reactions to Generate Understanding through Evidence
From the article "Modeling Periodic Patterns" in The Science Teacher, NSTA September 2017
Perhaps we might regard chemical experiments being taught in high school from a different perspective … one of a thinking process over a proof. Though redox and electronegativity are among many examples of concepts that must be learned and tested for, what makes them believable? Chemical reactions commonly used in high school potentially offer broader opportunities for the NGSS Teacher to engage students in learning to work the evidence. While it is always faster and easier (for a teacher) to simply give working definitions and draw models, processing given experiments for different purposes is far more memorable and open to valuable, formative discussion. This is what Ms. Dusty Carroll of Seneca High School is doing.
Ms. Carroll successfully used concepts in common reactions to provoke evidence rather than simply show a predictable response. Her high school classes were asked to draw on the evidence for thinking how two simple concepts - electron affinity and ionization energy - work. The NGSS approach to understanding changes occurring during a chemical reaction needed a working phenomenon for this – namely, the snatching of electrons from weaker atomic structures. While this paradigm is universally intriguing to humans, it is also evidential. Metals with acids and halogen/halide reactions provide the means to demonstrate the evidence desirable in showing comparative atomic structure functions and properties. For Dusty, it was another way to use chemistry to strengthen her students’ confidence in doing science as well as their reasoning abilities.
We have all found it difficult at times to generate a “wow” factor during lab work; but when Dusty’s students were asked to think through a reaction on their own based on evidence seen, she found that students were more pleased with their success since something they had considered difficult to understand was actually possible to show.
When asked what drew her to write an article on this topic, she modestly replied she wanted to share her ideas; but also wanted others to understand that she continues to tweak labs for deeper purposes and approaches within the NGSS. But isn’t that exactly what science is all about?
I asked if she considered any Real World applications in teaching her Property Reaction topics. She replied that perhaps the broader considerations of how materials work together should be considered, especially within the area of materials science. She advocates working with the students in seeing “patterns” with properties and posing questions. She asks her students to look for the “why” aspect. When there is no prior knowledge to use, patterns are very useful.
When I asked what motivated her students, she was quick to indicate that color really draws in the students when working with chemical reactions. Just like with elementary children, bubbles, color, temperature and other changes focus the interest. She also uses catchy phrases like “stealing an electron”; but later substitutes more appropriate worded phrases and definitions. Nevertheless, the metaphors certainly assist the visualization! Accurate communication is something she insists on, and notebooks are kept with drawings encouraged. Even though mistakes are made due to lack of experience (judging color, time of reaction, degree of change), these are qualitative errors that correct themselves over time. Students are not yet coming to high school with solid understandings of properties and equations.
As for assessing these developing skills in her students, she goes for the “storyline” approach that Mike Heinz introduced during one of his assessment seminars - reasoning being emphasized by evidence.
Dusty is delighted to share her ideas and has with her high school peers. She likes the Peer Review process and uses the feedback. As an active member of NJSTA, we hope to find more articles in NSTA’s The Science Teacher by her as she harnesses more of the NGSS approach.
Dusty Carroll can be reached at Seneca High School, Tabernacle, NJ or at
Submitted by Linda Burroughs, NJSTA Vice-President