Question

Assertion :According to Mendeleev, the properties of elements are a periodic function of their atomic weights. Reason: Mendeleev left the gap under aluminium and a gap under silicon, and called these elements Eka-Aluminium and Eka-Silicon.

• A. Assertion and reason both are correct statements and reason is the correct explanation for assertion.
• B. Assertion and reason both are correct statements but the reason is not the correct explanation for assertion
• C. Assertion is correct statement but reason is wrong statement.
• D. Assertion and reason both are wrong statements.

Answer 1

The correct option is B Assertion and reason both are correct statements but the reason is not the correct explanation for assertion

Mendeleev proposed the law on the basis that on arranging elements in the increasing order of their atomic weights, similarities appear in physical and chemical properties at regular intervals.
Eka-Aluminium and Eka-Silicon are gallium and germanium. They were undiscovered at the time when Mendeleev published his periodic table.
Both Assertion and Reason are correct statements, but the reason is not the correct explanation of the assertion.