What is the mass of 1 mole of NaCl and 1 mole of Nitrogen

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.

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

What volume would 2.25 moles of ne has occupy at stp?