Chemistry-Periodic Table

NEET Chemistry Periodic Table Assertion Reason Question

Type: Assertion Reason-assertion-Hard-Class 11

Assertion (A): The modern periodic law is based on atomic number rather than atomic mass. | Reason (R): The first ionization enthalpy of sodium is lower than that of magnesium.

A

Both A and R are true, and R is the correct explanation of A.

B

Both A and R are true, but R is not the correct explanation of A.

C

A is true, but R is false.

D

A is false.

Correct Answer

Option B

Detailed Explanation

The modern periodic law is indeed based on atomic number, but the given reason about ionization enthalpy does not explain this assertion. The periodic law is a result of the discovery of atomic number's fundamental role, not ionization enthalpy trends.

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