Which element was discovered by Marie and Pierre Curie?

• A. Radium (Ra)
• B. Gold (Au)
• C. Mercury (Hg)
• D. Platinum (Pt)

Answer: (A)

Verified step by step guidance

1. Understand the context of the question: it asks which element was discovered by Marie and Pierre Curie.
2. Recall the historical contributions of Marie and Pierre Curie in the field of chemistry and physics, particularly their work on radioactivity.
3. Identify that the Curies discovered two elements: polonium (Po) and radium (Ra), both radioactive elements.
4. From the given options (Gold, Mercury, Platinum, Radium), recognize that radium (Ra) is the element discovered by the Curies.
5. Conclude that the correct answer is radium (Ra) based on the historical discovery by Marie and Pierre Curie.