Why is the atomic mass of iron, 55.845 amu, most similar to the mass of iron-56, yet less than 56 amu? The atomic mass is the si

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max2010maxim

1 month ago

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Why is the atomic mass of iron, 55.845 amu, most similar to the mass of iron-56, yet less than 56 amu? The atomic mass is the si

mple average of the masses of the two most abundant isotopes. Iron‑56 is the most abundant isotope, so the atomic mass of iron is most similar to the mass of iron‑56. The second most abundant isotope is iron‑54, which reduces the atomic mass to less than 56 amu. The atomic mass is the weighted average of the masses of all of the isotopes. Iron‑56 is the most abundant isotope, so the atomic mass of iron is most similar to the mass of iron‑56. The second most abundant isotope is iron‑54, which reduces the atomic mass to less than 56 amu. The atomic mass is the weighted average of the masses of the two most abundant isotopes. Iron‑56 is the most abundant isotope, so the atomic mass of iron is most similar to the mass of iron‑56. The second most abundant isotope is iron‑54, which reduces the atomic mass to less than 56 amu. The atomic mass is the simple average of the masses of all of the isotopes. Iron‑56 is the most abundant isotope, so the atomic mass of iron is most similar to the mass of iron‑56. The second most abundant isotope is iron‑54, which reduces the atomic mass to less than 56 amu.

Chemistry

1 answer:

eduard [2.7K] · Answer 1 · 2026-02-22T15:30:31+03:00

Answer:

Iron-56 is the predominant isotope, making the atomic mass of iron closest to that of iron-56.

Explanation:

The isotopic abundance for iron is:

⁵⁴Fe: 5.82%

⁵⁶Fe: 91.66%

⁵⁷Fe: 2.19%

⁵⁸Fe: 0.33%

This indicates that Iron-56 is the most prevalent isotope of iron.

Considering that the atomic mass is derived from the sum of the masses of the isotopes adjusted for their abundance, and given that Iron-56 is the most common isotope, it follows that the atomic mass of Fe is likely to be similar to that of ⁵⁶Fe due to its higher abundance.

The accurate option is: