Question

What is the mass of one u(unified mass) in grams ?

Answer 1

For any element, its atomic mass in AMU is equal to the weight of 1 mole of the element in grams. For example, all natural isotopes of oxygen collectively have an atomic mass of15.999 AMU, so one mole of oxygen weighs exactly 15.999 

Answer 2

For any element, its atomic mass in AMU is equal to the weight of 1 mole of the element in grams. For example, all natural isotopes of oxygen collectively have an atomic mass of 15.999 AMU, so one mole of oxygen weighs exactly 15.999 grams.