Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum

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Sub Image2:Macro to Micro Structures
1) Atoms and Molecules2) Macro to Micro Structures 3) Energetics and Dynamics 4) Theory and Practice in Chemical Systems 5) Chemical Design 6) The Chemistry of Life 7) Chemistry and the Environment 8) Chemistry at the Interface

Unit 8.3 Analyzing the Unknown
Students apply chemical principles to problem solving. Analytical methods for analyzing solutions of unknown composition are presented.
Video program cues: 16:00 — 28:00

Forensic chemistry

"Everything’s different. No case is ever the same. I worked as an analytical chemist and everything is routine, it’s the same, but in case work, there’s a lot more challenge, and trying to figure out something, and it is satisfying when you make the connection between the victim and the suspect, and it’s kind of neat when you find something that nobody else ever thought of doing. General unknowns are a lot of fun, too, because they’re a big challenge: what is it, where did it come from, and you try to identify a complete unknown, because it could be anything in the world that could be used as evidence. So, it’s always a big challenge. I like the puzzle, the mystery of trying to figure the things out. Typically what we do is we get a sample, and we take just a few grams on the spatula, and we burn it. That would be a positive flame test, because it goes with a flash, it does that hissing sound, and it gives off a puff of white smoke. That would be a characteristic of black powder. Some explosives also burn but black powder has these distinctive burn characteristics that people can identify… from the way it reacts with the flame you can tell, and of course, under the microscope they are very different."

Rebecca Huff
FBI Explosives Unit


Identifying solutions laboratory

Felix Muhiga teaches about finding the chemical composition of solutions by using a common test for ions.



  • This site, from ChemSource, gives a complete lab procedure for cation analysis.

The chemistry of DNA

"The foundation of DNA, when you go to molecular biology or to molecular biochemistry, obviously has its basic roots in chemistry. Acid-base relationships, protein chemistry, all these kinds of things, which typically are found in biochemistry but you still have to know acid-base reactions and things like that, are from chemistry."

Melissa Smrz


Heinhorst, S.; Cannon, G. (2001)' Nature: "Green" Chemistry, Natural Antioxidants, and a DNA-Fueled Machine, 'Journal of Chemical Education, Vol. 78, No. 2, pp: 150-151.

Proceed to Unit 8.4 arrow

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