Off the Beaten Path

This cache is the final addition to my mini-series. "Off the beaten path" will be either a pair, or trio of caches, near the road US 27, but not quite on the road themselves. They will not be more than one mile away from their posted coordinates, so if your solution is farther away than that, you've done something wrong. Good luck finding them! The location of the final cache will be revealed through a cyberquest. Six questions await, each giving a single digit to fill in the coordinates through this formula; N 39° 51.ABC' W 84° 54.DEF' BEWARE!!! This cache focuses on your knowledge of chemistry to reveal the final coordinates... and some of these questions are DIFFICULT without prior chemistry knowledge, and some may even take more than a few simple Google searches.  This one has been designed to be the hardest of the three in this series. Assume all atoms are normal (no ions or isotopes) unless otherwise said, and round all answers to the nearest whole number.

A= (Atomic Number for Oxygen) - (Atomic Number for Lithium)

B= Deuterium is a specific isotope of a Hydrogen atom. What would the atomic mass of one atom of this isotope, plus a notmal hydrogen atom?

Balance this chemical equation to find C. (That is, make sure the same number of each element is on each side of the equation.)

_Fe₂O₃ → _Fe+_O₂

C= The sum of the two coefficients on the right hand side of the balancing equation.

D= (The atomic mass of a neutron) - (The atomic mass of an proton)

E= (Amount of atoms in one molecule of ethane) - (Amount of electrons in one standard atom of Lithium)

F= A x (Amount of protons in a hydrogen atom)

Happy caching everyone! 

Nearby caches I recommend checking out if you are passing through town:

GC1AZQD - Last Train To Cacheville

GCT3AJ - Trailzend?

GC1WJPK - A National Road Welcome

GC1WKYZ - The Mummy and The Mastadon

GCA33B9 - Winnie's Cache