I use the GEMS series a LOT when I teach since it falls in line with my teaching style and it encourages inquiry without me having to come up with it all on my own. This particular lab is in "Chemical Reactions" and is appropriate for 6-8 and it is only $10.
Click on the picture for the link.
To go with this lab I created these cute mini books that you can pick up for free by clicking on it's picture. I've decided to use these this year as a way to help students organize their notes and make a topic easy to find in one specific area. If you think these are something you can use too, I am working on a growing bundle that will include mini books for all the areas I cover in chemistry. Right now the growing bundle of at least 10 mini books are on sale for $5 in my store. Once I begin adding others, the price will go up. I'll include 2 versions of each topic, one for students that need desk notes or that are absent and the other is a blank version. I actually use the first version as I scaffold what my expectations are.
Click on the picture for the download.
It can also be found in the freebie section.