Who realized that elements form compounds?

• A. Aristotle
• B. Robert Boyle
• C. Antoine Lavoisier
• D. Democritus

Answer: (B)

The idea being tested is that elements can combine to form new substances called compounds. Robert Boyle helped establish this view through careful experiments that showed substances once thought to be simple elements could actually be broken down into simpler substances, and that when elements join, they form new substances with different properties. His work emphasized testing how substances combine and separate, laying the groundwork for thinking of elements as the basic building blocks that can create compounds. This experimental approach clarified how chemical reactions reorganize materials into new compounds, which is why he’s the person associated with recognizing that elements form compounds.