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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…."
Link
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
Links
Atomic structure class
Tom Pratuch teaches Atomic Structure using the wrong model
of the "Annandale Atom".
Activity
Reading
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
Reading
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 |
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