In doing a real quick search for a balance/scale showing an equal amount of atoms on each side, and not finding one, decided to make one in 3D (yay Blender!). This is free to use, but not for commercial works. (right click and save-as - it is a 720p HD size.)
I like the easiness of just entering grades into a computer, finding the average, and I'm done.
But - I wish more schools (including post-secondary) were not so focused on percentages and averages, but actually looked at the proficiency and improvement of a student over time through a given unit. See this example article which is awesome!
I know which student I would use to pack my parachute. Before the "older" generation chime in, recognize that there are a lot of researchers and professionals who study assessment practices, what works and what doesn't, and how to properly guage student success before getting emotional about the 'fact' that an average grade is not necessarily the best method of showing what a student knows.
because I couldn't find one anywhere online through a google image search... Here's one that you can freely use. The bond angles are not accurate - I just threw it together in 3D quickly - but it shows the lewis/electron dot configuration of the valence levels, and how they are stolen from the red aluminum atoms to make 3+ cations, and received by the blue oxygen atoms to form 2- anions.
This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.
My workflow has been to link a youtube video, then immediately following, I create a "quiz" with only ~4 questions about the video to allow the students to demonstrate understanding of the concepts in the video. I use this as a formative assessment, to see areas where I need to focus, or give additional help to certain students.
Student engagement/buy-in is still challenging, even though there are assignments which are for report card marks and lecture videos only available online. I'm open to suggestions from others about this topic in the comments below...
For the students who have engaged - it is a good way to have a lighter view on the class topics - to find articles, youtube videos, or just comments and questions about science. It's familiar facebook-like appearance help in this case, also.
I will be doing more of a professional project around this topic, and creating a resource for the school admin and teaching staff which includes some research, interviews, and 'how-to' information. I'll be keeping the blog updated infrequently with details and findings as I work through the semester.