How many naturally occurring elements did the periodic law originally reveal analogies among?

Correct option is D

The correct answer is (d) 94

Explanation:

• The Periodic Law, as originally formulated by Dmitri Mendeleev in 1869, revealed analogies among the 94 naturally occurring elements known at the time.
• Mendeleev arranged elements in order of their atomic mass and noticed that elements with similar properties appeared at regular intervals.
• By 1869, 94 naturally occurring elements were known, and Mendeleev's periodic table helped to highlight their recurring patterns.

Information Booster:

• Mendeleev's periodic table was a significant step in organizing chemical elements, providing insight into their chemical properties and how they change across periods and groups.
• Mendeleev's predictions: He left gaps in his table for undiscovered elements, predicting their properties with remarkable accuracy, which was later proven true with the discovery of elements like gallium and germanium.
• The Periodic Law helped organize elements based on their atomic mass, which laid the groundwork for future discoveries, and was later refined by the use of atomic number.
• By 1913, Henry Moseley showed that the atomic number, rather than atomic mass, was a more accurate way to organize elements. This change led to the modern periodic table.
• Mendeleev's table significantly influenced the field of chemistry, as it revealed trends in chemical reactivity and physical properties.