How We Know: Spectroscopy in the first year and beyond Kristopher J. Ooms

Teaching from rich contexts in chemistry The implementations of case studies or context-based learning that provide deep and rich opportunities for learning diverse concepts through contexts, and that nurture the use of higher order cognitive skills to connect concepts and apply the knowledge gained to new contexts. “context-based/STS approaches provide as good a development of understanding as more conventional approaches.” “very strong evidence that context-based/STS approaches foster more positive attitudes to school science than conventional courses” Bennet, Lubben, Hogarth, Sci. Ed. 2007, 91, 347 – 370

Unpacking 3 questions the guide our teaching… Why we care… How we know… What we know… What content do we as educators want our students to know? What data, techniques and/or models does the scientific community use to determine what we know? How does this knowledge benefit our students and their understanding of chemistry in the world?

How we know…

Spectroscopy in the first year AtomicIR NMR Mass Spec Text A√√ X√ Text B√XX√ Text C√XXX Text D√XXX

Spectroscopy in the first year

Homebuilt spectrometer for under $250 Vanderveen, J.R.; Martin, B.; Ooms, K.J. “Developing tools for undergraduate spectroscopy: an inexpensive visible light spectrometer” J. Chem. Ed., 2013, 90,

R = 8000! Homebuilt spectrometer: Solar spectrum

Varian Inc. - Cary 50 UV-Vis spectrophotometer Cost: approx $ CND King’s – you’ve got to be kidding -1 spectrophotometer Cost: approx $250 CND Vibrational Spectrum for I 2

Spectroscopy in the first year AtomicIR NMR Mass Spec Text A√√ X√ Text B√XX√ Text C√XXX Text D√XXX “For example, each substance absorbs a uniquely different set of infrared frequencies. A plot of the wavelengths absorbed versus the intensities of absorption is called an infrared absorptions spectrum. It can be used to identify a compound, because each infrared spectrum is as unique as a set of fingerprints.” Text A Pg.1078, the third last page. Discussed in relation to radioactive decay and isotopes.

Stumbling Blocks to Including More Spectroscopy in First Year Theory first approach: Students need some quantum mechanics before they can appreciate spectroscopy. Atoms first approach: Students need to understand the details of the molecules before they can understand how spectroscopy probes molecular structure. Text book first approach: Students need the structure of a text and since spectroscopy isn’t in the text we can’t teach it.

How we know … CO 2 is related to warming Rich Context 1: Mass Spec, IR and Greenhouse Gasses

How we know … increased CO 2 leads to warming Rich Context 1: Mass Spec, IR and Greenhouse Gasses

How we know … how to differentiate one molecular structure from another Rich Context 2: Structure, Recognition, and NMR Spectroscopy

Conclusion Using Rich contexts and an Evidence-based approach to teaching introductory chemistry allows (requires) an introduction of spectroscopic techniques early in student’s chemistry education.

1) Students are confronted with chemistry as an experimental science. 2) Better understanding of how spectroscopy is used do determine structure and monitor chemical reactions. 3) Connect spectroscopy, evidence in chemistry, and the molecular world with social, global, and personal issues.

Leah Martin Visscher Peter Mahaffy Brian Martin Chem 201 students Acknowledgements… We owe it to our chemistry and non-chemistry majors to teach how we know about the molecular world.