Visualization Of Molecular Symmetry – Online Tools And Learning Processes

1. Visualization Of Molecular Symmetry – Online Tools And Learning Processes 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

2. Symmetry Is All Around Us • In life • In Art • In Chemistry

3. Introducing Symmetry • Are these objects symmetric? • How do we know that?

4. A Short Definition • Symmetry 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.

5. How Do We Know? • We rotate or reflect the object in our mind. Rotation Reflection

6. Molecular Symmetry • Are these molecules symmetric? • How can we help students visualize the symmetry?

7. Visualization Of Hidden Parts • Present molecules in 3D • Allow students to rotate structures on screen • Present symmetry elements on screen • Allow students to draw their own elements

8. Molecules Are 3D Objects water vitamin C methane

9. Molecules Rotate In Space water methane vitamin C

10. Molecular Symmetry Online Molecular Symmetry Online

11. Symmetry Toolkit http://telem.openu.ac.il/symmetry

12. 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.”

13. Molecules Are Dynamic • How much symmetry is lost due to vibration? • How can we visualize it?

14. Perfect symmetry is rare: Molecules are dynamic entities Both physical conditions and chemical environments creates structural distortions Minor substitutions creates major changes in the symmetry of a molecule Continuous Symmetry

15. The 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. Continuous Symmetry

16. Visualization Of Hidden Parts • Present molecules in 3D • Allow students to rotate the structure • Calculate symmetry measures in the background • Present original and resulting molecules interactively

17. CoSyM Website http://telem.openu.ac.il/symmetry/csm

18. Typical Problem • 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? Ammonia Hypothetical structure with 180º rotation axis

19. 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."

20. Summary • Online 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.

21. With Appreciation To: • Colleagues: • Dr. Paul Gorsky – The Open University of Israel • Dr. 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

22. Thank You!