3-D Angles
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Visualizing three-dimensional structures is a major hurdle for chemistry students. Compounding the difficulty, chemists use three different concepts to imply geometry, although there is no obvious geometric information in two of them. The bond angle (a geometric construct) can be known from noting either the hybridization of the central atom (a quantum mechanical construct) or the coordination number (the number of other atoms bonded to the central atom).
3-D Angles uses pattern recognition principles introduced through rapid repeated exposure to three concepts to teach students to intuitively associate the three terms together in order to be able to correctly recognize the molecular structure from limited information.
Platforms
Windows 98, Me, 2000, or XP
Current Version
2.0.1 (10/04/04)
Setup Program
3-D_Angles_Setup.exe (1.56 MB;
1,642,670 bytes)
Note: If you run 3-D Angles and the program's display appears blank, you need to obtain updated video card drivers that support the OpenGL graphics library. Send e-mail to Tim Su if you continue to have problems after you have done this.
Developer
Stephen Michael Schimpf
This exploration is an animation that requires the
Shockwave plugin.
It works with both Internet Explorer and Netscape, on both Mac and PC.
Click
here to see this animation
Crystalline Solids
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Visualizing three-dimensional structures is a major hurdle for chemistry students. Many molecular modeling programs have been designed to assist visualizing organic structures; fewer exist for crystalline compounds.
Crystalline Solids attempts to meet that need. The program provides easily manipulated three-dimensional models of fundamental crystal structures. Students can turn and rotate either single or multiple unit cells of any of the fourteen Bravis lattice structures. They can toggle between structures where the atoms are represented by small spheres, similar to ball-and-stick models, or large spheres, which simulate the space-filling nature of the atoms in a crystal.
Close-packed cubic and hexagonal structures provide the additional features of studying interstitial sites/holes, or close-packed planes and slip planes. Students can place atoms in small or medium sites and turn on or off the axes between the atom in the site and its nearest neighbors, or the edges of the tetrahedron or the octahedron formed by these nearest neighbours. Visualizing packing patterns is simplified by highlighting sequential close-packed planes or slip planes.
At UCLA the program is used routinely in general chemistry, in intermediate inorganic chemistry, in a graduate solid-state class and in a chemical engineering course. We have longitudinal evaluation data on its effectiveness in general chemistry.
Platforms
Windows 98, Me, 2000, or XP
Current Version
2.0.1 (04/20/05)
Setup Program
Crystalline_Solids_Setup.exe
(1.56 MB; 1,636,985 bytes)
Note: If you run Crystalline Solids and the program's display appears blank, you need to obtain updated video card drivers that support the OpenGL graphics library. Send e-mail to Tim Su if you continue to have problems after you've done this.
Developer
Stephen Michael Schimpf
This exploration is a Web-based tutorial that requires the Chime plug-in.
Click here to see this tutorial
top
This exploration is an animation that is accompanied by a set of worksheets
which can be printed out for distribution to students.
Click here to see this animation (both PC and Mac)
Worksheets
Introduction to Dynamic Equilibrium (.pdf file, requires
Adobe Acrobat Reader)
Dynamic Equilibrium Exploration (.pdf file, requires
Adobe Acrobat Reader)
**A version of this exploration is also available via WebCT. WebCT is used to
deliver instructions, content, and to collect student responses.
Email cpr@nslc.ucla.edu for more
information about this option.
GraphLab
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GraphLab teaches basic principles and skills for graphing. The program is divided into four lessons: scaling, drawing a "best-fit" straight line, errors, and least-squares fit.
Scaling: Requires students to set the scales for graphs in which the variables that involve direct and inverse proportions and in which the scale involves exponents. Students must provide equally spaced intervals.
Best Fit Line: Students move a line with the mouse and place it so that the best fit of the data is obtained. The slope of the line must agree within 5% of the calculated least-squares-fit line.
Errors: Scientific data can contain either random and/or systematic errors. In this lesson, students must place the line to give a best fit and then decide based on the phenomena being described what kind of errors the data contain.
Least Squares Fit: In this lesson, students draw the least-squares line by minimizing the sum of the squares of the differentials, which is shown on the screen as they place the line on the data. The differentials are also shown to provide a visual sense of the minimization. Finally, students are confronted with an "outlier" when they are drawing the least-squares line. In each section students are presented with clearly stated principles and guidelines for graphing illustrated in an accompanying graph of real data from various science subject areas. Following each new principle, students are asked to summarize and evaluate that information. This informative phase is followed by an exercise phase in which students practice the skills.
Platforms
Windows 98, Me, 2000, or XP
Current Version
4.0.1 (10/04/04)
Setup Program
GraphLab_Setup.exe (408 KB; 418,641
bytes)
Worksheets
Graphlab Description (.pdf
file, requires Adobe
Acrobat Reader)
Graphlab Exercise (.pdf file,
requires Adobe
Acrobat Reader)
Developer
Stephen Michael Schimpf
top
Hybridization
This exploration is an animation that requires the
Shockwave plugin.
It works with both Internet Explorer and Netscape, on both Mac and PC.
Click here to see this animation
This exploration is a Web-based tutoria that requires the Chime plug-in.
Click here to see this tutorial
This exploration is a small program that must be downloaded onto your computer; only works with Excel 97 on a PC.
Click here to download this exploration (a Microsoft Excel file)
WebCT is used to deliver instructions,
content, and to collect student responses for this exploration.
Worksheets
Kinetics
Worksheets (.pdf file, requires
Adobe Acrobat Reader)
Kinetics Graphing Worksheets
(Microsoft Excel file)
Send
e-mail to cpr@nslc.ucla.edu for
more information about accessing this exploration.
Click here to see the list of animations
This animation requires the
Shockwave plug in.
It works
with both Internet Explorer and Netscape, on both Mac and PC.
Click
here to see this animation
These
are a series of animations that require the
Shockwave plugin.
They work best on PC's using Netscape (these animations each require a download
ranging from 200 KB to 3.8 MB in size).
Click here to see the list of animations This exploration is an animation that requires the
Shockwave plugin.
Click
here to see this animation Representations Chemists have developed advanced written notations to convey the structure
of molecules. Although the symbolism represents only the connectivity of the
atoms, these impoverished representations imply the specific geometry of the
molecule.
Representations trains students to relate the notation of the impoverished
drawing with the richness of the three dimensional structure of the molecule.
Random presentation of a variety of impoverished drawings, typical of
textbooks, are compared with three-dimensional models of rotating molecules
drawn using advanced lighting and rendering techniques. The models may be
correct or may include logical but incorrect interpretations of the drawing.
Students identify the accuracy of the model and receive corrective feedback if
appropriate.
Platforms
Current Version
top
Phase Diagrams
It works with both Internet Explorer and Netscape, on both Mac and PC.
top
Click image to view
at full size.
Windows 98, Me, 2000, or XP
2.0.1 (10/04/04)
Setup Program
Representations_Setup.exe
(1.58 MB; 1,659,818 bytes)
Developer
Stephen Michael Schimpf
WebSpectra
This site was established to provide chemistry students with NMR spectral
problems.
Interpretation of NMR spectra is a technique that requires practice - this site
provides 1H NMR and 13C NMR spectra of different compounds for students to
interpret. Hopefully, these problems will provide a useful resource to better
understand NMR spectroscopy.
This project is supported by Cambridge Isotope Laboratories, the UCLA
Department of Chemistry and Biochemistry, and the UCLA Science Challenge.
Platform
Web - Try WebSpectra
now
Developers
Craig Merlic
Barry Fam