Minechem is a mod that explores chemistry and some basic physics in the Minecraft world.
With a bit of effort, you can decompose the everyday items around you into compounds and elements.
You can then combine and re-assemble the elements into compounds and materials of your choosing.
Download the mod from CurseForge or the Github releases page
If you need a bit of help getting started, visit the Minechem wiki.
You can also get the latest (unstable) builds from the Minechem Jenkins build server
Minechem for 1.6.4 uses Universal Electricity: download the UE Core.
Minechem for 1.7.10 uses the RF system: download CoFHCore.
Minechem 5.0.5+ is licensed under the DBaJ (Don't Be a Jerk) non-commercial care-free license.
If you're feeling generous, Minechem has a Patreon page where you can support future development and show your appreciation of the time and effort spent bringing you a cool mod.