please explain step by step for me to be able to understand. thank you

a. A mole of any substance contains the same number of atoms. b. One mole of water contains Avogadro's number of atoms. Follow the problem solving strategy - Show all work for problems includin he correct number of significant figures. What is the molar mass of calcium sulfate? (Show work and include unit.) How many moles are in 1.501023 formula units of lithium phosphide? How many grams are in 5.66mol of calcium carbonate