Which major contribution is Dmitri Mendeleev best known for in the field of chemistry?

• A. Proposing the law of conservation of mass
• B. Developing the first widely accepted periodic table of elements
• C. Discovering the electron
• D. Inventing the atomic model with energy levels

Answer: (B)

Verified step by step guidance

1. Understand that Dmitri Mendeleev is a historical figure in chemistry known for organizing elements based on their properties.
2. Recall that the law of conservation of mass was established by Antoine Lavoisier, not Mendeleev.
3. Recognize that the discovery of the electron is credited to J.J. Thomson, and the atomic model with energy levels was developed by Niels Bohr.
4. Identify that Mendeleev's major contribution was creating the first widely accepted periodic table, which arranged elements by increasing atomic mass and predicted properties of undiscovered elements.
5. Conclude that the correct answer is that Mendeleev developed the first widely accepted periodic table of elements.