I had two activities planned today so half the kids played with the app Elements 4D while half did the lab from the American Chemical Society’s curriculum. The Elements 4D app apparently has been around for awhile but I just heard of it last week on a facebook page for science teachers. Its FREE and its awesome! You print out 6 different blocks, each block has 6 different elements on it, cut them out and fold them to make blocks – I used tape instead of glue. After you download the app you use the device’s camera to look at one of the blocks, the app will recognize it and then ‘animate’ the block, showing what the element looks like even as you pick up the block and move it around. The developer, DAQRI calls it augmented reality and its very cool. Even better, they have FREE lesson plans you can download and when you put two different elements that react in front of the camera it will tell you the compound it can form. When you push the blocks together so that they touch, they ‘react’ and the pictures change to show the compound. You can see in the photo below zinc chloride looks like a powder.
I had the students fill out a table with random elements of their chosing. They pick a block, put it in front of the camera and record the name of the element, its group number (column of periodic table), its color and state of matter (liquid, gas or solid) at room temperature. Then they tried to find combinations that would react and had to record element names and group numbers for both. A couple of the kids had ‘Aha!’ moments when they saw that elements from group 1 (Na, K, Li) all reacted with Cl from group 17 because group 1 elements have an extra electron they would like to get rid of while group 17 ‘wants’ an extra electron to fill their outer most shell. I may actually have my high school class do this activity as well tomorrow.
The lab students did was Chapter 6, lesson 6: Using Chemical Change to Identify an Unknown from the ACS curriculum. Students are to react 4 different powders with 4 different liquids and record the results – bubbles, color changes, etc. The lab says to do it on a piece of wax paper or laminate a grid but I used 24 well reaction plates since I had them. I already had a template I could print out for the kids but went ahead and labeled the columns and rows for them.
Students put one powder in the well plate at a time, so they put roughly 1/4 spatula of baking soda in the first column, wells A1, B1, C1 and D1. Then they took a pipette and dropped 5 drops of water in A1, got a different pipette and put 5 drops of vinegar in B1, and so on with the iodine solution (100 ml of water with a few drops of iodine) and the pH indicator. I did not have any universal indicator but had some bromothymol blue which goes from yellow (acid) to blue (base) which worked fine. After recording their observations on the chart they filled in the next column with the next powder and tested it with the different liquids.
When they had tested all four powders they were given an unknown powder and tested it the same way and were able to determine what it was by comparing to their previous results.
These two activities worked well together since neither took up a whole class period and it kept the kitchen counter, I mean lab table, from getting too crowded.