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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Metallic character decreases and non-metallic character increases on moving from left to right in a period. Reason (R) : It is due to increase in ionisation enthalpy and decrease in electron gain enthalpy, when one moves from left to right in a period. In the light of the above statements, choose the most appropriate answer from the options given below :

1. (A) is false but (R) is true.
2. (A) is true but (R) is false.
3. Both (A) and (R) are true and (R) is the correct explanation of (A)
4. Both (A) and (R) are correct but (R) is not the correct explanation of (A)

Correct answer: (A) is false but (R) is true.

Solution

The assertion is incorrect because while metallic character does decrease and non-metallic character increases across a period, the reason provided is misleading; ionization enthalpy generally increases, but electron gain enthalpy does not consistently decrease, making the reasoning flawed.

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