Question

question 6 of 14
iron has four naturally occuring isotopes: iron-54, iron-56, iron-57, and iron-58. the natural abundance of each of these isotopes is shown in the table.

isotope	natural abundance (%)
iron-56	91.72
iron-57	2.20
iron-58	0.28

identify the isotope that is least abundant on earth.
○ iron-56
○ iron-54
○ iron-57
○ iron-58

identify the isotope that is most abundant on earth.
○ iron-56
○ iron-58
○ iron-54
○ iron-57

identify the isotope with the smallest mass.
○ iron-57
○ iron-54
○ iron-58
○ iron-56

identify the isotope with the fewest neutrons.
○ iron-54
○ iron-57
○ iron-58
○ iron-56

Explanation:

First Sub - Question: Identify the least abundant isotope

To find the least abundant isotope, we compare the natural abundances (in percentage) of each isotope. The abundances are: iron - 54 (5.80%), iron - 56 (91.72%), iron - 57 (2.20%), iron - 58 (0.28%). The smallest percentage is 0.28% which corresponds to iron - 58.

We compare the natural abundances. The abundances are: iron - 54 (5.80%), iron - 56 (91.72%), iron - 57 (2.20%), iron - 58 (0.28%). The largest percentage is 91.72% which corresponds to iron - 56.

The mass number of an isotope is given in its name (e.g., iron - 54 has a mass number of 54, iron - 56 has 56, etc.). A smaller mass number means a smaller mass (since the mass number is approximately the mass of the isotope in atomic mass units). Comparing 54, 56, 57, 58, 54 is the smallest, so iron - 54 has the smallest mass.

Answer:

D. iron - 58

Second Sub - Question: Identify the most abundant isotope