Question: how many atoms are there in 1 amu?
Answer: Dividing 12 grams by this incredibly large number of atoms tells us that one carbon-12 atom weighs 1.99 x 10-23 grams. Since a carbon atom weighs 12 AMU, one AMU is equivalent to 1.66 x 10-24 grams. Conversely, one gram is equivalent to 6.022 x 1023 AMU, which is Avogadro's number.