Inbal Tuvi-AradDepartment of Natural Sciences, and The Chais Research Center for the Integration of Technology in Education, The Open University of Israel

Learning with Visualizations

Symmetry Is All Around UsIn life

In Art

In Chemistry

Introducing SymmetryAre these objects symmetric?How do we know that?

A Short DefinitionSymmetry is defined in terms of elements and

operations.Element – an axis, a plane, a point.Operation – rotation, reflection, inversion.

An operation is symmetric if the resulting object is identical to the original one.

How Do We Know?We rotate or reflect the object in our mind.

ReflectionRotation

Molecular SymmetryAre these molecules symmetric?How can we help students visualize the symmetry?

HC

H

HH

OH H

water

OH

OH

HO

OO

HO

vitamin Cmethane

Visualization Of Hidden PartsPresent molecules in 3DAllow students to rotate structures on screenPresent symmetry elements on screenAllow students to draw their own elements

Molecules Are 3D Objectswater

methane

vitamin C

Molecules Rotate In Space

water

methane

vitamin C

Molecular Symmetry Online

Molecular Symmetry Online

http://telem.openu.ac.il/symmetry

Symmetry Toolkit

Students’ Quotes“Before I couldn’t see anything. Now I do.”“I no longer need to imagine the structure in my

mind.”“I can see the symmetry element in my mind, but I’d

rather use the toolkit to draw it and check if I’m right.”

Molecules Are Dynamic

How much symmetry is lost due to vibration?How can we visualize it?

Continuous SymmetryPerfect symmetry is rare:Molecules are dynamic entitiesBoth physical conditions and chemical

environments creates structural distortionsMinor substitutions creates major changes

in the symmetry of a molecule

Continuous SymmetryThe Continuous Symmetry Measure determines the

distance of a given structure from perfect symmetry.

It can be used to compare between various distorted structures.

Symmetry becomes a continuous property of matter.

Visualization Of Hidden PartsPresent molecules in 3DAllow students to rotate the structureCalculate symmetry measures in the backgroundPresent original and resulting molecules interactively

CoSyM Website

http://telem.openu.ac.il/symmetry/csm

Typical Problem

Ammonia Hypothetical structure with 180º rotation axis

Is there an axis around which we can rotate the molecule by 180 and obtain an identical structure?

If not, how would a structure with such an axis look like?

Teachers’ Quotes"When I teach about molecular structure I describe

only rigid structures, I never imagined how molecules move."

"I felt a big difference… the visualization opened my eyes."

"Now I am going to look at molecules in a different way. There is no sharp distinction between symmetry and no symmetry - there are a lot of levels in the middle."

SummaryOnline Symmetry tools help students visualize the

hidden process of solving problems.Visualization of molecular symmetry, and continuous

symmetry contribute to deeper understanding of molecular structure.

Website tools can be used at various content levels and for various teaching and learning purposes.

Exposing teachers to advanced scientific content can improve the way they teach more basic topics.

With Appreciation To:Colleagues:

Dr. Paul Gorsky – The Open University of IsraelDr. Ron Blonder – The Weizmann Institute of Science

Molecular Symmetry Online Team:Dov Garmise, Vered Tooby-Fishberg, Zeev Perl

CoSyM website Team:Open University team: Dr. Dina Yogev-Einot, Dov Garmise,

Uri Shefi, Roy Sharoni, Itai Har-Even, Nadav Peer, Zeev Perl Hebrew University team: Prof. David Avnir, Dr. Mark Pinsky,

Dr. Alexander Sterkin, Shadi Laham, Chaim Dryzon

Thank You!