Early Use of AP Insight with Honors Chemistry: Atomic Mass, Mass Spectrometry, and Dalton's Postulates

AP Insight

College Board offers an excellent online resource for teachers and students. It's not free, but my school district pays the bill. AP Insight provides curriculum outlines, teaching ideas and resources, student handouts, and digitally-graded assessments. I have elected to begin using the resources in first semester honors chemistry.

Early in the semester, my students research the evolution of the atomic theory. They read about John Dalton and his postulates. Many students can recite the postulates, but they often accept all of Dalton's ideas as truth. He is in the textbook and the internet, right? This year, the students' level of analysis was different.

Here's how:

  1. We studied the history/evolution of atomic theory AFTER the atomic structure unit. They actually understood what was discovered and the role it played in the atom. 
  2. I incorporated American Modeling Teachers' Association (AMTA) handouts on mass spectrometry. Students learned very simply how isotopes are separated and measured by mass. They viewed diagrams of mass spectrometers and discussed the significance of greater mass and its effect on the path of the isotope.
  3. Students learned to read simple mass spectrographs and calculate average atomic masses. All accomplished using one AMTA handout and an AP Insight handout. We spent approximately 30 minutes of class.
  4. Students then accessed AP Insight and solved four or five assessment questions requiring them to apply mass spectrometry concepts to support or debunk Dalton's postulates.
  5. This AP Insight assessment opened the door for conversations about JJ Thomson's cathode ray experiment and Aston's revision to develop mass spectrometry.

My students are now able to use data for calculations, but they are also able to draw connections between current methods and technologies and early theories. Students finally understand that scientific knowledge is evolving, and even Dalton was incorrect in his well accepted postulates. For the first time, the kids understand isotopes, atomic mass, laws of definite and multiple proportions, cathode rays, and mass spectrometry beyond memorizing definitions or rote calculations. Thank you, AP Insight and AMTA.