[huwfczdp] Chemistry simulator

Create a chemistry simulator similar in spirit to the many mechanics physics simulators that abound in games and real science, e.g., Kerbal Space Program.  This of course is likely monstrously difficult.  Perhaps it can give the correct answer when it knows it, and "don't know" when it doesn't, which will be often.

Motivation is education: experiment with chemistry without a lab.

In the absence of being able to do a realistic simulation, simplify the laws of chemistry to make something fun.  Minecraft is an extreme example.