Which of the following is closest to the atomic mass of neon (Ne)?

• A. 20.18 u
• B. 12.01 u
• C. 22.99 u
• D. 18.00 u

Answer: (A)

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 neon (Ne) is a noble gas with atomic number 10, and its atomic mass is typically found on the periodic table.
3. Compare the given options to the known atomic masses of common elements: 12.01 u corresponds to carbon, 22.99 u corresponds to sodium, and 18.00 u corresponds to water (H2O) or oxygen-related values, none of which match neon.
4. Recognize that the atomic mass of neon is approximately 20.18 u, which is closest to the given correct answer.
5. Therefore, select the value closest to 20.18 u as the atomic mass of neon.