Sure, let's analyze the given information step-by-step.
1. Identify the isotopes and their atomic masses:
- Argon-36 has an atomic mass of approximately 36 atomic mass units (amu).
- Argon-38 has an atomic mass of approximately 38 amu.
- Argon-40 has an atomic mass of approximately 40 amu.
2. Determine the given average atomic mass of Argon:
- The average atomic mass of argon is given to be approximately 39.948 amu.
3. Relate the average atomic mass to the abundance of isotopes:
- The average atomic mass of an element is calculated based on the weighted average of the masses of its isotopes, factoring in their natural abundance.
- Mathematically, it can be expressed as:
[tex]\[
\text{Average Atomic Mass} = \sum (\text{Fractional Abundance} \times \text{Isotope Mass})
\][/tex]
4. Compare the given average atomic mass with the isotopic masses:
- The given average atomic mass is very close to the atomic mass of argon-40 (≈ 40 amu).
- This suggests that argon-40 is likely to contribute the most to the average atomic mass because it is the closest in value.
5. Conclusion:
- Given that the average atomic mass is approximately 39.948 amu and this value is closest to 40 amu, we can conclude that argon-40 is the most abundant isotope in nature.
Therefore, argon-40 is the most abundant isotope of argon based on the given average atomic mass.
