24
12Mg
that Mg is supost to be between the 2 numbers not on the bottom or top specifically.
2007-10-08 10:53:33 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
The Atomic number of Magnesium is 12 -- that equals the number of protons in the nucleus.
The Mass number of your magnesium isotope is 24 -- that equals the number of protons (12, from the atomic number) plus the number of neutrons (in this case, also 12) in the nucleus.
The mass number MUST ALWAYS be equal to or greater than the atomic number (because you can't have negative numbers of neutrons, right?!)
2007-10-08 11:08:23 · answer #1 · answered by Dave_Stark 7 · 0⤊ 0⤋
isotope is an atom of same element, but different atomic mass. Thus Cl 35 has [35- atomic no of neutrons[pl see the at no. ] Cl 37 has two more neutrons . now the mass nos of 35 & 37 contribute respectively 75 & 25 %. & you can calculate the ultimate mass - that is what is given in the periodic table. For these , pl make it a point to read the text & understand, if in doubt, pl . ask teacher or classmates.
2016-05-19 01:43:05 · answer #2 · answered by ? 3 · 0⤊ 0⤋