Which property did Dmitri Mendeleev use to organize the elements in his original periodic table?

• A. Density
• B. Atomic mass
• C. Electronegativity
• D. Atomic number

Answer: (B)

Verified step by step guidance

1. Understand that Dmitri Mendeleev organized the elements based on a specific property that showed a repeating pattern of chemical properties.
2. Recall that Mendeleev arranged the elements in order of increasing atomic mass, which was the best-known property at his time.
3. Recognize that by ordering elements by atomic mass, Mendeleev was able to group elements with similar chemical behaviors into columns (groups).
4. Note that other properties like atomic number and electronegativity were not known or used by Mendeleev when he created his periodic table.
5. Conclude that the key property Mendeleev used to organize the elements was atomic mass.