Question

Calculate the atomic mass of element X if there are two isotopes of this element (X-24 and X-28) and 75% of all X atoms are X-28 isotopes? 52 amu 26 amu 4 amu 27 amu

Answer 1

[(25% x 24) + (75% x 28)]/100 = 27 amu. The answer is d. 27 amu

Answer 2

Answer:

27 amu

Explanation:

If X-28= 75%

Then X-24 = 100-75= 25%

Then

(28 × 0.75) + (24× 0.25) = 21 + 6= 27 amu

NB

The sum of all the relative abundances of isotopes must be 100%.

The sum of the products of isotope abundance and mass for each isotope gives the relative atomic mass for the element