What is the atomic mass of neon?
Actually Neon would be lested as having an atomic mass of about 20.18 because of a mixute of isotopes.
Z= Atomic number the number of protons in the nucleus which defines the element. in this case Z=10 and this means neon but there is also 10 neurons in the nucleus of the major isotope whcich gives it ^20Ne. The other minor isotope is ^22Ne which has 12 neutrons and 10 protons in its nucleus.