Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum

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Sub Image1:Atoms and Molecules
1) Atoms and Molecules
2) 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 1.2 Atomic Structure
Various kinds of models for atomic structure are presented: scientific models, teaching models and models (correct or incorrect) that students use to understand atomic structure.
Video program cues: 5:00-13:15

What is an atom?

Students’ ideas

"I think an atom is a little thing; it's got neutrons and protons in the middle, in the nucleus, and then around it…it has got electrons, and it's in everything…."

"I think an atom is the building block of everything. Its nucleus is made from protons and neutrons and it's surrounded by electrons in orbit…."


This page is designed for younger students and notes some misconceptions about atomic structure.

Models for visualization

Teachers’ forum

"When I start the year in chemistry, one thing I do is write the words for chemistry in Japanese on the board. What it means in Japanese is to study changes, and that really helps me to get across the study that accompanies change: Atoms to molecules, different states of matter, and such."

Gannon Sugimura
Annandale High School, Virginia

"I use jewelry to introduce the difference between an element and a compound, because it's something that everybody is familiar with, especially gold. And talking about purity and impurities in gold jewelry and how that relates to quadrates…and I can get my kids to participate in that."

Dr. Michael Clarke
Duke Ellington School of the Arts, Washington, D.C.

"One of our biggest problems is that 90% of what they see is not really on the level of what they're expected to know. You see the color change, you see it happening, but they have to understand it on the level of atoms and molecules…. It's something that they are never ever going to see, so we've gone to something that they can physically manipulate on the table…."

Caryn Galatis
Thomas A. Edison High School, Virginia

"Since our school team is called the Annandale Atoms, we have a really weird-looking atom symbol. Basically, I take this symbol, bring it into class, and have them tear it apart and tell me what's wrong; this is not what we've been taught that an atom looks like, because this is an image from 1955 when our school was built; they thought the atom looked like that and it's wrong!"

Catherine Del Conte
Annandale High School, Virginia

"Worse than that, it has taken us three years to find out that that drove all the understandings that were going on and it took what we went through to make students draw things. What we found out was that their understanding of the atoms stylizes three elongated orbitals, …which represents the three parts of the atom: the neutron went on one, the proton went on the other, the electron went on the third…when we discovered that we suddenly understood why they were performing all of the reactions and calculations wrong. It took us three years to come out with a program to eliminate that…."

Tom Pratuch
Annandale High School, Virginia


Atomic structure class

Tom Pratuch teaches Atomic Structure using the wrong model of the "Annandale Atom".



Giunta, C.J. (2001) 'Using History to Teach Scientific Method: The Role of Errors', 'Journal of Chemical Education, Vol. 78, No. 5, pp: 623-627.

The modern atomic theory

"The modern theory of the atom, developed in the 1930's with the quantum mechanical model, which describes mathematically how electrons have both particle-like and wave-like character, hasn't changed since then and is the best one we've got…. The analogy I use often is propeller blades moving quickly… the nucleus, of course, is extremely small, and we will not be able to see it anyway, but just as we know that the blades are there, when the blades are moving around, you get a perception of a smudged, cloudy look. That's not a bad analogy to the way electrons are arranged in an atom…."

Dr. Roy Tasker
Associate Professor, Univ. of Western Sydney


Leary, J.J. and Kippeny, T.C. (1999) 'A Framework for Presenting the Modern Atom', 'Journal of Chemical Education, Vol. 76, No. 9, pp: 1217-1218.

Proceed to Unit 1.3 arrow

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