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The element rhenium (Re) has two naturally occurring isotopes, 185Re and 187Re, with an average atomic mass of 186.207 u. Rhenium is 62.60% 187Re, and the atomic mass of 187Re is 186.956 u. Calculate the mass of 185Re.

Respuesta :

Answer:

The mass of the 185Re is 184.974 u

Explanation:

All elements in nature are present as mix several Isotopes. The Average Atomic mass is the weighted product of each Isotope times its specific atomic mass. Then, for the Rhenium:

[tex]62.20% * 186.956 u + (100% -62.20%) * 185ReAM = 186.207 u[/tex]

Where 185ReAM stands for the Atomic mass of the 185Re isotope. Then solving for this:

[tex]185ReAM=\frac{186.956 u-0.6220*186.956 u}{1-0.6220}=184.974 u[/tex]

Remember that 100%=1, 62.20%=0.6220