An atom consists of 11 electrons, 12 neutrons, and a number of protons. which information will be most in determining the atom's charge?

I would say, the number of electrons. 

Why?

Because the number of electrons is equal to the number of protons, and the number of protons is equal to the atomic number, so we can look for atomic #11.

Then, we can identifiy the element, which is Sodium

Then, we can locate sodium on the periodic table and find it's charge, which would be +1.

The number of electrons and protons both are needed to determine the charge if the atom loses or gains electron(s) to form ions.