A board book that introduces chemistry to kids through the use of comparison activities. #ChemistryForToddlers #STEM The Pre-order store is open as a campaign extension. It will be open as a replacement to the cancelled #ACSPhilly meeting where they were going to be sold as a presale at an Expo booth. This will be open until 4/15/2020. After that, you will have to wait until it is officially launched on June 2, 2020.