If you put copper metal in a silver nitrate solution, the solution becomes blue and you get silver metal. Ag+ is becoming Ag and Cu is becoming Cu++. The students see both oxidation and reduction happening - and happening at the same time. If you do it close to Christmas you can use the copper filament to make a Christmas tree, and then you get a nice silver on the Christmas tree. They know that it was a colourless ion solution, but then they can see silver on the Christmas tree. So they can easily see the reduction.
Use two screens in a lecture and then turn one off and go to the visualiser and spend time on the visualiser drawing things or solving problems or writing something. And at that point the class becomes engaged. So when you’re using PowerPoint, unless you’re really good with it, they’ll disengage. If you start writing and drawing structures and things on the visualiser, they start doing it and then it becomes much more interactive - they’re working from the visualiser then they’re back to the PowerPoint and then back to the visualiser again.
Use a lot of demonstrations - actually doing reactions at the front of the class. You can't actually see the electrons moving when you're doing the reaction, but still it helps to use demonstrations. Beware of possible misinterpretations that could arise when doing demonstrations.
3D modelling software is very good. There are some Java Applets that show 3D visualisations of orbitals. You just select whichever orbital you want and you can rotate it and view it from different angles.
Use models to illustrate shapes formed by molecules. Or use balloons to illustrate bonding pairs and electron pair repulsions leading to the determination of molecular shape You can show them a tetrahedron and an octahedron etc.
For this particular topic, there are some quite nice simulations of wave functions and of orbitals and similar things on the web that can be used to visualise what orbitals look like, and what wave functions look like. They seem to like it.
Use balloons to illustrate bonding pairs and electron pair repulsions leading to the determination of molecular shape For example, if you tie 6 balloons together, it automatically forms the octahedral shape. Then each time you pop one, they rearrange themselves to sequentially form the other shapes: trigonal bipyramidal, tetrahedral, trigonal planar and linear. It’s visually appealing, a concrete example and memorable for students. Also, popping the balloons wakes the students up!
Use clicker questions in a lecture. Use multiple choice questions and you can see the class distribution, that is, what percentage of students got it right. If a lot of them don’t get it right, go through it again. That really helps to get the feedback from students about their understanding. Use it for other topics as well but this will be one topic to use it for in a big class.
