What is the difference between Atomic weight and mass number?
They are not the same. The atomic weight averages the mass of all the isotopes of a particular atom together, and I think the percentage of each isotope is accounted for in the statistical process of averaging, but I’m not sure about that. The mass number is the number of protons and neutrons added together for a particular isotope of an atom.
According to my Chemistry lessons, the atomic number is the number of protons in the nucleus, whilst the mass number tells you the total number of protons and neutrons in the nucleus. With the atomic number, you can also tell how many electrons there are. I’m not sure about Atomic weight though. Mass is how heavy it is in kilograms and micrograms and stuff, but weight is measured in newtons. So maybe it has something to do with that?
“The atomic weight of each element is included along with the element symbol in the periodic table. It is important to note that no one atom has a mass equal to that of the atomic weight. Remember: the atomic weight represents that average mass of the atoms.” This seems fairly clear and may be helpful.
