Consider the statements below and identify the correct answer.
Statement I: Among chemical properties, Mendeleev concentrated on the compounds formed by elements with carbon and hydrogen.
Statement II: He selected these elements as they are less reactive and formed compounds with few elements.

Correct option is D

The correct answer is (d) Statement I is correct, Statement II is incorrect.

Statement I:
"Among chemical properties, Mendeleev concentrated on the compounds formed by elements with carbon and hydrogen."
This statement is correct. Mendeleev did indeed focus on the compounds formed by carbon and hydrogen (hydrocarbons) as part of his study of chemical properties. He recognized the significance of these compounds in understanding the relationships between elements.
Statement II:
"He selected these elements as they are less reactive and formed compounds with few elements."
This statement is incorrect. While Mendeleev certainly focused on chemical properties in his periodic table, the claim that he selected elements based on being "less reactive" is incorrect. Many elements that Mendeleev considered in his work (such as alkali metals) are actually highly reactive. Mendeleev's goal was to understand how elements combined and behaved in relation to one another, not just based on their reactivity.
Conclusion:
Statement I is correct.
Statement II is incorrect.