Apologia Chemistry: Density

After the Periodic Table test and the equipment test tomorrow, my plan is to do two labs: Accuracy and Precision Lab and Flinn's Density Lab.  I am comfortable using this data shee t because I've purchased more than six of these kits.  This is an alternate lab using the two methods: volume by displacement and volume by geometry. 

The lab kit sold by Flinn has the objects described in the data sheet above.  We use metal cubes, wood blocks, marbles, cylinders, etc.  Not all of the objects fit into a graduated cylinder and the volume must be determined by direct measurement using geometry.  I ask the kids to hypothesize which method, displacement or geometry, is more accurate.  They compare their answers with known values, using a table with accepted values for common objects.  Be sure to have a small cylinder of water--say 10 mL.  The kids can weigh the water and measure the volume in the cylinder to determine the volume. 

This is an opportunity to introduce percent error calculations and crying...

I plan to use an alternate lab for accuracy and precision.  For this lab, the kids use a plastic cup, ruler or meter stick, and a sponge.  The kids wet the sponges and drop it one meter to hit the cup.  If they miss the cup, they need to measure the distance the sponge landed from the cup.  The kids collect 30 data points and calculate the mean, median, and mode.  It's a good way to introduce experimental design and review simple statistics.  I'm pretty sure, we have enough material here for tomorrow.