How many elements have been found to occur naturally on Earth?

• A. 86
• B. 92
• C. 118
• D. 104

Answer: (B)

Verified step by step guidance

1. Understand the question: It asks for the number of elements that occur naturally on Earth, meaning elements that are found in nature without human synthesis.
2. Recall that the periodic table currently lists 118 elements in total, but not all of these are naturally occurring; some are synthetic and created in laboratories.
3. Identify the range of naturally occurring elements: Elements with atomic numbers 1 (Hydrogen) through 92 (Uranium) are known to occur naturally on Earth.
4. Recognize that elements beyond atomic number 92 are synthetic and do not occur naturally; they are produced artificially in nuclear reactors or particle accelerators.
5. Conclude that the number of naturally occurring elements on Earth is 92, corresponding to all elements from Hydrogen to Uranium inclusive.