Which of the following elements has the greatest atomic mass?

• A. Copper (Cu)
• B. Uranium (U)
• C. Calcium (Ca)
• D. Iron (Fe)

Answer: (B)

Verified step by step guidance

1. Understand that atomic mass refers to the average mass of atoms of an element, measured in atomic mass units (amu), and is roughly equivalent to the number of protons and neutrons in the nucleus.
2. Recall or look up the atomic masses of the given elements: Copper (Cu), Uranium (U), Calcium (Ca), and Iron (Fe).
3. Compare the atomic masses of these elements by noting their positions on the periodic table and their approximate atomic masses: Calcium (~40 amu), Iron (~56 amu), Copper (~63.5 amu), and Uranium (~238 amu).
4. Recognize that Uranium has a significantly higher atomic mass than the other elements listed because it has many more protons and neutrons in its nucleus.
5. Conclude that Uranium (U) has the greatest atomic mass among the given options.