How do we find the number of neutrons in the ""^31P31P isotope?

1 Answer
anor277
Jan 20, 2017

Simply subtract 1515 from 3131:

31-15="number of neutrons in the phosphorus isotope"=1631−15=number of neutrons in the phosphorus isotope=16

Explanation:

For the ""_15^31P3115P isotope, "Z, the atomic number"Z, the atomic number, the subscript, is superfluous. The element is phosphorus, and ZZ, "the atomic number"the atomic number == 1515 BY DEFINITION.

The "mass number"mass number, the superscript, is the number of massive particles, protons and neutrons, contained in the nucleus of the isotope, and this is given by the superscript. This is something you really should get your head round. Hydrogen has 3 common isotopes, ""^1H, "protium", ""^2H, "deuterium",1H,protium,2H,deuterium, and "tritium",""^3H. tritium,3H. Can you tell me the number of neutrons each nucleus contains?

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