Given that the abundant of isotope 54Fe, 56Fe and 57Fe are 5 %, 90 % and 5 % respectively, the atomic mass of Fe is :

Question

Given that the abundant of isotope 54Fe, 56Fe and 57Fe are 5 %, 90 % and 5 % respectively, the atomic mass of Fe is : (A) 55.85 (B) 55.95 (C) 55.75 (D) 56.05

Tardigrade Admin · Accepted Answer

From the given relative abundance, the average weight of Fe can be calculated as A= ( 54 × 5 +56 × 90 + 57 × 5/100) = 55.95

Q. Given that the abundant of isotope $_{54} F e$ , $_{56} F e$ and $_{57} F e$ are $5%$ , $90%$ and $5%$ respectively, the atomic mass of $F e$ is :

55.85

55.95

55.75

56.05

From the given relative abundance, the average weight of $F e$ can be calculated as
$A = \frac{54 \times 5 + 56 \times 90 + 57 \times 5}{100} = 55.95$

Q. Given that the abundant of isotope 54​Fe, 56​Fe and 57​Fe are 5%, 90% and 5% respectively, the atomic mass of Fe is :