General Chemistry Online: Construction Kits Construction Kits let you assemble problem solutions, chemical formulas, chemical equations, and other chemical objects piece by piece or step by step. You'll need Macromedia's free Flash Player to use them. Flash Player comes pre-installed with most modern browsers, but if you're using an older browser you may need to download Flash Player here (version 6 or better is required). in Public bookmarkswith chemicalchemistryequationsflashkitsproblemsimulationssolutions