Which of the following is closest to the atomic mass of nickel (Ni)?

• A. 58.69 u
• B. 65.39 u
• C. 63.55 u
• D. 55.85 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 or look up the atomic mass of nickel (Ni) on the periodic table, which is typically given as a decimal value reflecting this weighted average.
3. Compare the given options (65.39 u, 63.55 u, 55.85 u) to the known atomic mass of nickel to identify which is closest.
4. Note that 55.85 u corresponds to iron (Fe), 65.39 u corresponds to zinc (Zn), and 63.55 u corresponds to copper (Cu), so these are not the atomic mass of nickel.
5. Conclude that the atomic mass closest to nickel's actual atomic mass (approximately 58.69 u) is not listed among the options, but 58.69 u is the correct value for nickel.