Which of the following is the largest and heaviest element in its natural elemental form?

• A. Gold (Au)
• B. Uranium (U)
• C. Mercury (Hg)
• D. Lead (Pb)

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the question is asking for the element that is both the largest (in atomic size) and heaviest (in atomic mass) among the given options in their natural elemental form.
2. Step 2: Recall that atomic size generally increases down a group in the periodic table, but atomic mass is a more direct measure of how heavy an element is, based on the number of protons and neutrons in its nucleus.
3. Step 3: Identify the atomic numbers and atomic masses of the elements: Gold (Au) has atomic number 79, Mercury (Hg) 80, Lead (Pb) 82, and Uranium (U) 92. Atomic mass increases with atomic number for these elements.
4. Step 4: Compare the atomic masses: Uranium has the highest atomic number and atomic mass among the listed elements, making it the heaviest naturally occurring element here.
5. Step 5: Conclude that Uranium (U) is the largest and heaviest element in its natural elemental form among the options given.