inbal tuvi-arad department of natural sciences, and the chais research center for the integration of...
TRANSCRIPT
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!