DIY Particulate Models

Particulate diagrams are all the rage in chemical education. The new AP Chemistry CED emphasizes particulate model use in Science Practice 1: Models and Representations. Particulate models help students visualize the invisible sub-microscopic world of chemistry. This can help students understand and explain macroscopic phenomena.

Many ChemEd X bloggers (Meyers, Gardner, and Ragan) have discussed their benefits. Recently, ChemEd X blogger Michael Farabaugh discussed how he uses particulate diagrams to identify and address chemical misconceptions in AP Chemistry. While textbooks and resources are starting to contain more and more particulate representations, I often can’t find the particulate model I want to use for a practice problem, in-class example, card sort, or assessment.

Creating your own particulate diagrams may seem daunting. In this blog post, I would like to share how I create professional-looking particulate diagrams using free tools. When I had to create models as a writer for the Flinn Chemistry POGIL book, I learned how to draw particulate diagrams in Google Slides and Powerpoint. These free programs give you maximum control over the location of objects to produce professional-looking results. I should mention that I teach at a Google school with 1:1 Chromebooks so my examples will use Google Slides, but the techniques are easily transferable to Microsoft Powerpoint.

Drawing lab equipment 

I use Chemix.org to draw lab equipment. Chemix is a free online editor for drawing lab equipment and diagrams. Once I create the lab diagram in Chemix, I download the picture or take a screenshot by using Ctrl + Alt + Switch Window (box with two lines in the top row) keys on my Chromebook (figure 1). I then insert the picture into a slide on Google Slides. Chemix is really impressive and they are updating and improving throughout the year. Check them out!

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Figure 1: Drawing and downloading Chemix image

Finding pictures  

I use Google to find supplemental images (figure 2). When searching for an image, I select “Tools” on the top bar and then “Transparent” and “Labeled for noncommercial reuse with modification.” "Transparent" means the image will not have a white box around it and improves the look of the image when it is layered. "Labeled for noncommercial reuse" means that I am respecting the original artist’s wishes. Once I find the image I want, I right-click and “copy” (or Ctrl+C) and then paste it (Ctril+V) in my Google Slide. 

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Figure 2: Finding supplemental images using Google

Make molecules using shapes  

When it is time to create molecules, atoms, particles, or compounds, I use the shape button in the menu bar. I press the "Shift" key when drawing the shape to keep it symmetrical (figure 3). This is especially helpful when making different sized circles. It ensures my circles do not turn into ovals. I use the "Fill" button to add a color or gradient to the object. I also like the look of my particles when I set the border weight to 3px or 4px.

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Figure 3: Google Slides Toolbar Options

Group shapes to make molecules 

Once I make a molecule, I group the shapes together by selecting all of the shapes and pressing Ctrl+Alt+G or going to the "Arrange" tab in the menu (figure 4). Grouping shapes makes it easier to use the copy and paste technique to “clone” molecules. It helps speed up the drawing process. I also right-click or use the "Arrange" tab to help align, distribute, and rotate my objects. If my object is hidden by other objects, I use the "Order" option to move the object in front of or behind other objects.

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Figure 4: Group shapes to make molecules

Make it exact 

Sometimes I have a hard time using my mouse to get my object in the perfect spot. I select "Format Options" from the "Format" tab in the menu or when I right-click (figure 5). Under the "Format Options" menu on the right side of the screen, I use the "Position Option" to change numbers until I get it just right.

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Figure 5: Position options
 

Saving the particulate diagram 

When I am done, I download the slide as a JPEG. Select “File” “Download” and “JPEG image” to save to your file (figure 6). Powerpoint has an option to select a part of the slide (ie. flask) and right-click to download the part of the slide you selected.

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Figure 6: How to save particulate diagram

Now that I have the particulate diagram saved as a JPEG, I can add the image into any document (worksheet, quiz, test) I like.

So far I have been able to draw any crazy model I dream up using Google Slides and Powerpoint. There is a learning curve to this, but over time the process becomes easier and faster. I really like the freedom drawing my own particulate models gives me. Hopefully, you have learned some tricks to make drawing particulate diagrams easier! Happy drawing!