What is the Name of RbC2H3O2

Does anyone know a lot about how to: - calculate mass of magnesium metal - calculate the actual yield of magnesium oxide - calculate the theoretical yield of mgo - calculate the percent yield of mgo - determine the percent yield of mgo - determine the average percent yield of mgo i had to do an online lab and its asking these questions but i have no idea where to start or how to be able to find these things. i can post the chart of the data from the lab or if you can tell me exactly how i can find each.

If the atomic mass of an atom is 34 and the atom contains 13 protons, how many neutrons does the atom contain?

Ineed to find the answer of this question because i dont understand it