Question: how many moles in 1 kg of hydrogen?
Answer: The atomic mass of hydrogen is 1 g/mole. To make up 1 kilogram or 1000 g of hydrogen element, 1000 moles of hydrogen is required. Each mole has a Avogadro's number of atoms or atoms. Thus, 1 kg hydrogen element or 1000 moles of hydrogen have atoms (or 1000 times the Avogadro's number).