Which significant scientific contribution is Dmitri Mendeleev best known for?

• A. He invented the spectroscope.
• B. He discovered the electron.
• C. He created the first widely recognized periodic table of elements.
• D. He developed the atomic theory.

Answer: (C)

Verified step by step guidance

1. Identify the key scientific contributions listed in the problem: invention of the spectroscope, discovery of the electron, creation of the periodic table, and development of atomic theory.
2. Recall the historical context and achievements of Dmitri Mendeleev, a Russian chemist from the 19th century.
3. Understand that Mendeleev is most famous for organizing elements based on their atomic masses and properties, which led to the creation of the first widely recognized periodic table.
4. Recognize that the periodic table arranged elements in a way that predicted the existence and properties of elements not yet discovered, a major advancement in chemistry.
5. Conclude that among the options, Mendeleev's best-known contribution is the creation of the first widely recognized periodic table of elements.