Which of the following is closest to the atomic mass of xenon (Xe)?

• A. 39.10 u
• B. 54.94 u
• C. 207.2 u
• D. 131.29 u

Answer: (D)

Verified step by step guidance

1. Understand that the atomic mass of an element is the weighted average mass of all its naturally occurring isotopes, measured in atomic mass units (u).
2. Recall that xenon (Xe) is a noble gas with an atomic number of 54, and its atomic mass is typically found on the periodic table.
3. Compare the given options to the known atomic masses of elements near xenon on the periodic table: 39.10 u corresponds roughly to potassium (K), 54.94 u to manganese (Mn), and 207.2 u to lead (Pb).
4. Recognize that the atomic mass of xenon is approximately 131.29 u, which fits logically between the given options and matches the known value from the periodic table.
5. Conclude that the closest atomic mass to xenon among the options provided is 131.29 u.