Which scientist discovered the radioactive element radium, a key milestone in the study of radioactivity and nuclear science?

Introduction / Context:
The discovery of radium marked a major advance in the understanding of radioactivity and opened the door to many applications in medicine and physics. Radium became famous both for its scientific importance and for the health risks associated with radiation. This question asks you to identify the scientist who discovered radium, a name that also appears frequently in questions about Nobel Prizes and pioneering women scientists.

Given Data / Assumptions:

• The element in question is radium, a highly radioactive metal.
• The focus is on the scientist who discovered this element.
• The options include scientists from different centuries and fields.
• Only one of these names is correctly linked to the discovery of radium.

Concept / Approach:
Marie Curie, working together with her husband Pierre Curie, isolated and identified radium while researching radioactive materials such as pitchblende. Their work built on the earlier discovery of radioactivity by Henri Becquerel, and it earned Marie Curie multiple Nobel Prizes: in Physics and in Chemistry. Isaac Newton is known for classical mechanics and gravitation, and Benjamin Franklin for experiments with electricity and the lightning rod, not for radioactivity. Therefore, the scientist associated with the discovery of radium in standard GK is Marie Curie.

Step-by-Step Solution:
Step 1: Note the keyword radium, which is tightly linked to radioactivity and early nuclear research.Step 2: Recall that Marie Curie is the most famous scientist connected with radium and polonium.Step 3: Look at the answer choices and find Marie Curie as option B.Step 4: Recognise that Newton work predates the discovery of radioactivity, and Franklin interests were mainly in electricity and politics.Step 5: Select Marie Curie as the correct answer.

Verification / Alternative check:
Every standard chemistry or physics textbook that includes a discussion of radioactivity mentions the Curies work on radium. Biographies of Marie Curie highlight the difficult process of extracting radium from large quantities of ore. In contrast, Newton and Franklin biographies do not mention any work on radioactive elements. This clear separation of scientific contributions confirms that Marie Curie is the correct choice.

Why Other Options Are Wrong:
Isaac Newton is associated with laws of motion, gravitation and optics. Benjamin Franklin is known for his kite experiment and the invention of the lightning rod, as well as political leadership, but not for discovering elements. The option None of these is incorrect because the correct discoverer, Marie Curie, is explicitly present among the alternatives. Hence, only option B matches the historical facts about radium discovery.

Common Pitfalls:
Some candidates may confuse the discoverer of radioactivity, Henri Becquerel, with the discoverers of radium, the Curies. Others may simply pick a familiar big name like Newton without checking the field of work. To avoid such mistakes, it is useful to remember a simple mapping: Becquerel for the discovery of radioactivity, the Curies for radium and polonium, and Rutherford for the nuclear model of the atom. This mental framework helps in answering nuclear science GK questions accurately.

Final Answer:
Radium was discovered by the scientist Marie Curie.