The atomic mass unit is equivalent to 1 of the mass of a neutral atom of carbon.
What is Atomic Mass Unit?
It is defined as one out of twelve parts of the mass of the neutral atom of the most abundant isotope of carbon, that is, carbon 12.
By this definition, it is obvious that the atomic mass unit of elements is measured with respect to the mass of a neutral atom of carbon 12 - not hydrogen, gold, or oxygen.
More on the atomic mass unit can be found here: https://brainly.com/question/489186
