Unit 1.7 Building Molecules
This section deals with ways to enhance student understanding about molecular structures. Balloons are used to illustrate the shapes of bonding orbitals in atoms.
Video program cues: 42:40-57:20

Relativity of atoms

"Atoms really are not the central thing in chemistry at all because they are like the Lego blocks that are used to build things; the molecules are much more interesting, they're combinations of atoms together. And then of course what people don't realize is that when you take two atoms together and form a molecule or some other substance, that other substance is completely different from the character of the separate atoms…. Hydrogen atoms are extremely reactive, oxygen atoms are very reactive. If you combine them together, you get H₂O, which is some non-reactive substance…but if you get hydrogen peroxide…that's a very reactive molecule…."

Dr. Roy Tasker
Associate Professor, University of Western Sydney

Link

• Three dimensional images of atomic structure and bonding can be found here, along with concise explanations for bonding arrangements. An NSTA SciLinks site.

How to teach new concepts

"Many times I try to figure out what they already know about the topic, and if I can find any fact to start with, which they've learned in a previous grade, I work and expand from there, and let them know where we are going. Something they've learned in biology or in another course or everyday life, and then go on from there…."

Sharon Walton
Watkins Mill High School, Maryland

• Scroll down this page for links to a variety of teaching theories and methods. Most are not science-specific.

Molecular geometry activity

Sharon Walton teaches about molecular geometry according to VSEPR rules by using balloons.

Activity

• Teacher’s Guide [PDF]
• Students’ Guide [PDF]

Link

• An excellent illustrated tutorial on VSEPR theory

Readings

Jones, M.B. (2001) 'Molecular Modeling in the Undergraduate Chemistry Curriculum' Journal of Chemical Education, Vol. 78, no.8, pp:867- 868

Parker, J. (1997) 'VSEPR Theory Demo' Journal of Chemical Education, Vol.74, no.7,p:776

Hanson, D. reviews (2001) 'Orbitals in Chemistry: A Modern Guide for Students', (Victor M. Gil, author), Journal of Chemical Education, Vol.78, no.9, p:1184

Martin, J.D. (2001) 'From the Wood-Shop to Crystal Engineering: Teaching Three-Dimensional Chemistry' Journal of Chemical Education, Vol.78, no.9, pp:1195-1197

People learn differently

"One of the most important things that a chemistry teacher has to be aware of is learning students' patterns, the fact that people learn in different ways, and try to make the subject approachable to students. What is logical to us might not be logical to them and that's where you need to start looking out for ways to make things more concrete for them and build the abstract from that."

Irene Walsh
St. Andrew's Episcopal School, Maryland

Teaching chemistry

"…If I were teaching…I would first try to give them the fundamentals, of why that’s important, why we're interested in the Periodic Table, why we're interested in radiation, where all our elements come from, It's really exciting-how this came to be, and what processes are involved."

Professor Darleane Hoffman
Professor of Chemistry, UC-Berkeley

Proceed to Workshop 2