A hypothetical pure element consists entirely of two isotopes. The natural percent abundance of the isotope with mass 25.5 u is 78.8 percent. The other isotope has mass 29.5 u. Calculate the atomic weight of the naturally occurring element.

Question

A hypothetical pure element consists entirely of two isotopes.  The natural percent abundance of the isotope with mass 25.5 u is 78.8 percent.  The other isotope has mass 29.5 u. Calculate the atomic weight of the naturally occurring element.

DrBob222 · Answer

(0.788&25.5)+(1-0.788)*X = 29.5 Solve for X.