Question: how many gram atoms are there in one atom?
Answer: From the Periodic Table of Elements, one sees that one mole of hydrogen atoms weighs 1 gram while one mole of oxygen atoms weighs 16 grams. What is this mole thing? A mole is a convenient counting unit whenever one is dealing with numbers of atoms or molecules. It is equal to Avogadro's number (NA), namely 6.022 x1023.