Which of the following elements has the largest atomic mass?

• A. Lead (Pb)
• B. Uranium (U)
• C. Osmium (Os)
• D. Oganesson (Og)

Answer: (D)

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 proportional to the number of protons and neutrons in the nucleus.
2. Recall or look up the atomic masses of the given elements: Lead (Pb), Uranium (U), Osmium (Os), and Oganesson (Og). These values are typically found on the periodic table or in reference materials.
3. Compare the atomic masses of Lead, Uranium, and Osmium to see which one is the heaviest among them. Note that Uranium is known for having a very high atomic mass due to its large number of protons and neutrons.
4. Consider Oganesson (Og), which is a superheavy synthetic element with an atomic number of 118, making it heavier than the other elements listed. Its atomic mass is higher because it has more protons and neutrons.
5. Conclude that among the elements listed, Oganesson (Og) has the largest atomic mass due to its position at the bottom of the periodic table with the highest atomic number.