Question

Rhenium (Re) is made up of 37.4% 185Re and 62.6% 187Re

The atomic mass of 185Re is 184.953 amu. The atomic mass of 187Re is 186.956 amu
What is the average atomic mass of rhenium?

Answer 1

Average atomic mass of Rhenium = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100

Average atomic mass of Rhenium = (184 .953×37.4)+(186.956×62.6) /100

Average atomic mass of Rhenium = 6917.2422 + 11703.4456 / 100

Average atomic mass of Rhenium = 18620.6878 / 100

Average atomic mass of Rhenium = 186.207 amu.

Answer 2

Average atomic mass of Rhenium = 186.207 amu.

Step-by-step explanation:

Given data:

Abundance of R¹⁸⁵ = 37.4%

Abundance of R¹⁸⁷ = 62.6%

Atomic mass of R¹⁸⁵ = 184 .953 amu

Atomic mass of R¹⁸⁷ = 186.956 amu

Average atomic mass = ?

Solution:

Average atomic mass of Rhenium = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100

Average atomic mass of Rhenium = (184 .953×37.4)+(186.956×62.6) /100

Average atomic mass of Rhenium = 6917.2422 + 11703.4456 / 100

Average atomic mass of Rhenium = 18620.6878 / 100

Average atomic mass of Rhenium = 186.207 amu.