Allen, A'Lester

A'Lester Allen is a physical chemistry graduate student researcher in Prof. Jin Zhang's lab. He graduated with a B.S. in Chemistry from Stanford University and an M.S. in Materials Engineering from San Jose State University. He utilizes electromagnetic theory to design nanostructures for applications in surface-enhanced Raman scattering based bio-sensors. A'Lester enjoys learning and is committed to helping others gain an equitable STEM education. A'Lester is also a good cook and enjoys hosting dinner parties.




Teaching Activity Summary

Name of Teaching Activity: Acid-Base Inquiry Activity "OH-, what the H+?!" 

Teaching Venue & Date: WEST 2019, Sept 18-19 2019

Learners: 16 community-college transfer students.

Reflection on how learners engaged with a STEM practice during the inquiry:

OH-, what the H+?! is an activity using acid-base chemistry. We aimed to provide each learner with several opportunities to explain their thinking using results. First, there was a demonstration of a color change. Each learner was encouraged to make observations then form a hypothesis about the chemistry involved. Next, the learners were encouraged to design a set of experiments to test their hypothesis. This activity involved isolating and changing a single variable. We encouraged the learners to record their goals, experimental design thoughts, and conclusions in a lab notebook. The last few practices centered on scientific communication. We encouraged group discussions with their lab partners throughout the activity and facilitated a poster session as the final activity. At every step in the process, the learners were encouraged to draw conclusions based on experimental evidence. Their observations informed an initial hypothesis. A common observation was that the solution affected the color. The experimental design focused on obtaining enough results to verify or disprove their hypothesis. Through the experiments, the students proposed reasons why the solution affected the color. Their questioning often led to discussions about molecular structure. Lastly, the conclusions that the learners made were based on experimental evidence. The learners were prompted to think about changes in the molecular structure that could result in a color change. They used conjugate acid and base pairs to understand which areas of the molecule could change then specific pH values to understand how the molecular structures changed. This process resulting in the students gaining insight into fundamental aspects of acid-base chemistry.