This exercise makes use of a web-based tool to review quantum numbers of the orbitals of the hydrogen atom and to visualize atomic orbitals in 3D. Students are asked to draw the 1s-, 2p- and 3d-orbitals.
The student should be able to
- identify atomic orbitals by their quantum numbers and by their letter labels.
- describe and draw the 3D shape of a 1s-, 2p- and 3d-orbital (showing only angular nodes)
- have an appreciation of the spatial orientation and 3D nature of these atomic orbitals
3D Glasses enhance the students' perception of the 3D nature of the orbitals. The glasses are available for <$20 per 50 glasses from your favorite online retailer.
Access to the web.
Prior to this activity, students were introduced to atomic orbitals in lecture (of a first-semester introductory general chemistry class). The organization of the class and associated lab was such that I was able to run this exercise as an "in-lab" activity (to complement a lab discussion) for lab sections of up to 16 students. The lab sections met in a classroom with a computer for each student.
After a brief overview (and handing out the 3D glasses), I took students through navigating the web resource up to the 1s orbital. The remaining exercises the students completed at their own pace. In designing this exercise, I wanted to set the time aside for students to appreciate the spatial nature of atomic orbitals - the "Dotted Model" in particular led to the most numbers of comments from the students. Reactions to drawing out the orbitals was mixed. A handful of students claimed not to be artistic enough to draw the orbitals (they managed just fine); most enjoyed the 3D visualization.
I collected the worksheets to ensure that students completed the exercises. Worksheets were graded for correctness and completeness and received a small bonus for extra efforts.
With all the answer provided on the web site, nearly all students completed the worksheet correctly. Few students took short-cuts and attempted to rush through the exercises with a minimum of attention. For most part, students took the time to work through each step of the exercises and to generate diagrams to the best of their abilities. Quite a few students produced beautifully drawn orbitals with spatial perspectives.