<span>Mass number is the number of protons and neutrons in an atom, and it tells us about the mass of the atom in amu, or atomic mass units. Atomic mass is the average mass of all the isotopes of a certain type.</span>
<span>Mass number found on the periodic table</span>
Yeah, a lot faster than sound.
Yes what do u need help with
NaHCO3 is the right answer
