Mendeleev left Russia in the late 1800's to traveled forward through time to see the advances that had been made with his creation. Before he returned, he left a treasure chest of chemical prizes, and to show that you can teach an old dog new tricks, he left the following clues to its location:
(11, 5) (16,4) (2,2) (18,1) (15,2) (16,5) (7,5) (17,2) (7,6)
This cache has a chemistry theme! (In case you haven't noticed, I am truly a geek! But don't be intimidated; the solution is quite easy.). It initial contents contained, along with the typical cache fare, a National Mole Day fridge magnet and a National Mole Day lapel pin. But not to worry - leave what you want - everything is made of chemicals anyway, right?
You can check your answers for this puzzle on Geochecker.com.