[haqntroz] Element cards

Create a deck of cards, one for each element.  On the front, nuclear properties, e.g., isotopes and radioactive decay.  On the back, chemical properties, e.g., oxidation states.  Not sure where density should go, a product of both.

Chemistry is the science of the outermost electron shell, while nuclear science is of course about the nucleus.  The filled inner electron shells get no love.