What is the percent by mass of sodium in na2so4?

Who is better, messi or cristiano, i need this for a chemistry class. asap

Which produce would best increase the amount of heat energy that is actually gained by calorimeter b

Ican determine the molar mass of an element by looking on the under the atomic mass for the element. for example the molar mass of phosphorus is 30.974 grams/mole. avogadro’s number tells me the amount of representative particles in 1 mole of any substance. this means 12.011 gram sample of carbon and a 32.0 gram sample of sulfur have the same number of atoms.