Why was Mendeleev's periodic table widely accepted by the scientific community?

• A. It was the first table to include all known elements at the time.
• B. It arranged elements strictly by increasing atomic number.
• C. It successfully predicted the existence and properties of undiscovered elements.
• D. It grouped elements based on their color and physical appearance.

Answer: (C)

Verified step by step guidance

1. Understand the historical context: Mendeleev created the periodic table in the 19th century when many elements were known, but some were still undiscovered.
2. Recognize that Mendeleev arranged elements primarily by increasing atomic mass, not atomic number, which was not yet known at the time.
3. Note that Mendeleev left gaps in his table where no known elements fit, predicting that these gaps corresponded to undiscovered elements.
4. Appreciate that Mendeleev predicted the properties of these missing elements based on the trends in his table, which was a novel and powerful approach.
5. Understand that the scientific community widely accepted Mendeleev's table because his predictions were later confirmed by the discovery of new elements with properties close to his forecasts.