If protons and neutrons each give one atomic mass unit to the weight of the atom, then why are the atomic masses listed on the periodic table not whole numbers?
2007-06-18 17:56:07 · 4 answers · asked by wonderwoman 1 in Science & Mathematics ➔ Chemistry
cause theres more than one total mass number you can find the mass unit and the regular mass of the element that why there two nummbers under the elements on the periodic table so you can find the total mass number of all protons and nuetrons in the element
2007-06-18 18:07:17 · answer #1 · answered by Anonymous · 0⤊ 0⤋
a. Electrons have some weight
b. The formation of a nucleus leads to a difference in mass from what is expected by simple addition of proton and neutron masses.
2007-06-19 01:06:56 · answer #2 · answered by cattbarf 7 · 0⤊ 0⤋
They are the averages of all known isotopes of that atom...
This plus the fact that electrons still have mass.... just not very much (9.108 X 10-28 grams)
2007-06-19 01:03:37 · answer #3 · answered by Anonymous · 0⤊ 0⤋
they are not whole because the presence of isotopes
average atomic masses are mean weight of all isotopes of an element
2007-06-19 00:59:45 · answer #4 · answered by ghulamalimurtaza 3 · 0⤊ 0⤋