What is the molar mass of a substance?

a.) the mass in grams of one mole of a substance
b.) the number of particles in one gram of a substance
c.) the number of moles in one gram of a substance
d.) the mass in grams of one particle of a substance

Covalent bonds are formed between metals and boiling points true or false

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.

It is important to wear proper protective equipment in lab even when not actively performing experiments because accidents can affect any researcher, even one not working on an experiment. select the best answer from the choices provided