Question

Calculate the mass number for a fictional element. The element has three isotopes with the following abundances and masses: 22.5 % is 43.2 g/mole 26.9 % is 44.9 g/mole 50.6 % is 45.9 g/mole

Answer 1

Answer:

45.0235

Explanation:

The atomic weight of any element can be found by multiplying the abundance of an isotope of that element by the atomic mass of the element.  The obtained results then add together. This equation can be used with elements with two or more isotopes. Since this fictional element has three isotopes, we will add together these three, after multiplying their abundance by corresponding atomic masses.

First, you need to divide percentage (abundance of an element) by 100 to get the decimal version.:

22.5%/100 = 0.225

Then, you multiply obtained result by the atomic mass of the corresponding isotope:

0.225 x 43.2 g/mole = 9.72 g/mole

You need to do the same with the remaining two isotopes:

0.269 x 44.9 g/mole = 12.0781 g/mole

0.506 x 45.9 g/mole = 23.2254 g/mole

The final result is:

9.72 + 12.0781 + 23.2254 = 45.0235  This is the atomic weight of fictional element