Ah sorry for the inconvenience. I'll add some description in the game page later today.
For now, you can input Fe and Pb into the activator, It'll output unstabled Pb, unstabled Pb will become Hg (atom num - 2) as time goes by.
you can make a long path to home so they have time to decay. or just an dead path, and connect the path after they become Hg.
then you can collect those Hg to Home base.
then you can build container, which filter stable items out. Also put Hg and Fe to Activator cause Hg unstable and produce new elements...