Which chemist is credited with discovering the element sodium and isolating it using electrolysis?

Introduction / Context:
Sodium is a highly reactive metal that plays an important role in chemistry and industry. Its discovery and isolation were part of a broader effort to identify elements using new techniques of electrolysis in the early nineteenth century. This question asks which chemist is credited with discovering sodium as an element and isolating it from compounds, a common fact in periodic table history and general science exams.

Given Data / Assumptions:

• The element is sodium, a reactive alkali metal.
• The discovery involved electrolysis techniques.
• The options list people connected to photography, atomic physics and automobiles.
• Only one name belongs to a chemist famous for isolating reactive metals using electricity.

Concept / Approach:
Humphry Davy, a British chemist, used electrolysis to isolate several reactive metals, including sodium and potassium, from their compounds. His experiments at the Royal Institution are well known in the history of chemistry. William Henry Fox Talbot is remembered for photographic innovations, J. J. Thomson for discovering the electron and Karl Benz for developing early petrol powered cars. None of these figures discovered sodium as an element. Therefore, Humphry Davy is the correct answer for this question.

Step-by-Step Solution:
Step 1: Recognise that the question focuses on discovering and isolating the chemical element sodium.Step 2: Recall that Humphry Davy used electrolysis to obtain highly reactive metals such as sodium from their compounds.Step 3: Examine the options and locate Humphry Davy as option A.Step 4: Recognise that William Henry Fox Talbot is associated with photography, not with alkali metals.Step 5: Recognise that J. J. Thomson worked on electrons and atomic structure rather than on isolating sodium.Step 6: Recognise that Karl Benz was an automobile engineer, not a chemist interested in electrolysis.Step 7: Select Humphry Davy as the correct answer.

Verification / Alternative check:
Chemistry textbooks recount how Davy passed electric current through molten or dissolved compounds to isolate sodium and potassium, demonstrating the power of electrolysis. Sodium is often listed alongside other elements like potassium and calcium as metals discovered by Davy. The other names in the options appear in chapters on photography, atomic theory or the history of cars, not in sections on alkali metal discovery. This confirms that Humphry Davy is the correct choice for exam style questions about sodium discovery.

Why Other Options Are Wrong:
William Henry Fox Talbot is known for early photographic processes and not for chemical element isolation. J. J. Thomson discovered the electron and proposed atomic models but did not discover sodium. Karl Benz designed early petrol powered vehicles and founded a car company, which is unrelated to chemical discoveries. As a result, options B, C and D cannot be correct answers to this question about the element sodium.

Common Pitfalls:
Because J. J. Thomson is strongly associated with atomic particles, some candidates may mistakenly choose him for any question about elements. Others might be unsure of Davy specific contributions. To avoid such confusion, memorise key associations: Davy and electrolysis of metals, Thomson and electron discovery, Talbot and photography, Benz and automobiles. This mental map will help you correctly answer many chemistry and general science MCQs.

Final Answer:
Sodium was discovered and isolated using electrolysis by Humphry Davy.