Using Computers in Chemical Education

A follow-up for questions asked by Brian Pankuch
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By Ken Costello — Physical Science Department — Mesa Community College
How do you tell when your innovations are working or when you have overdone it?
When something is overdone, what was at first an attention getter becomes a distraction. For example, some folks like to use sound effects when text or objects come on the screen. At first it will get attention and be useful in emphasizing certain points. If it is done too much, it becomes distracting and then annoying.

Designing PowerPoint is a lot like interior design. If everything has the same color, the room is boring. If it has too many colors, then it’s too busy and distracting. Deciding on a style or theme allows for variety but also restricts the design so there’s a pleasing balance. So a theme is a good idea with a PowerPoint presentation as well for the same reasons.

Can you give us an idea of these rules of composition you mentioned earlier?
Follow the rule of thirds. Imagine the screen divided into thirds like a tic-tac-toe. The main subject or subjects is placed at one of the intersections of the tic-tac-toe or on the line. For people the eyes are the main focus. So the eyes of people in the image should be along one of those thirds (usually the top third). In other words, the main subject on the screen is not placed dead center but usually one third from the top. When we look at a page, it’s where our eyes naturally go.

Keep the background simple. A busy background will detract from the main subject. Photographers will set the camera to purposely have the background out of focus so the subject (which is in sharp focus) will stand out more. For this reason, my backgrounds in PowerPoint are usually a simple gradient or a solid color. A subtle texture is OK, too.

Use leading lines to lead the viewer’s eyes to the subject. Leading lines are anything that draws attention to the main subject.

Increase the feeling of depth. Images are two dimensional. So there needs to be visual cues that give the feeling of depth. If a vanishing point is imagined or seen, that is one way to create depth. I created this collage using a street because it showed depth. Also notice the “face” of the mountain follows the rule of thirds.
How would you proceed if you were just starting to use these animation tools?

The first type of animation to use is the Entrance animations. Use them to bring items in as you talk about them. The idea is to always control what your audience is seeing. You bring them in on cue. If several points are on the screen, they are likely to be looking at something different than what you are talking about.


In the Animation window, choose Entrance and go to More Effects... I usually just use the ones labeled “Subtle” or "Moderate" in the "Add Entrance Effect" window. I use more energetic movements if the movement reinforces the message. Otherwise, the more energetic ones start to seem overdone. You can also use the "Exit" effects to get rid of items that you are no longer covering.

Could you show us how you would create an electron cloud, with electrons appearing and disappearing in a sphere around a nucleus?
At the end of my article I have a link to a PowerPoint called Hybridization. That shows electrons first orbiting as particles and then they turn into electron clouds that get hybridized. s, p, d, and hybrids are shown, plus animation of them hybridizing. Also at the beginning of the Demo PowerPoint there are examples of electrons orbiting behind a electron shell.

To make an electron cloud you use the circle shape in the Draw toolbar. When you stretch the circle out, hold down shift key to make it perfectly round. Click on the circle and then click on the "Fill tool." A menu pops up that includes a choice to go to "Fill Effects..." Choose that.

The Fill Effects window lets you choose colors for the sphere. To make it look transparent, experiment with the Transparency sliders to get different effects. Also choose the "Shading style" that says "From Center". This will create electron clouds and electron shells.

The appearing and disappearing of electrons is controlled by the Entrance effects. Click on the electron, then click the "Add Effect" button which will bring up four types of effects. You can use Entrance and Exit effects to bring electrons in and out.


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