JEE MAIN - Chemistry (2024 - 29th January Morning Shift - No. 2)

Given below are two statements : one is labelled as Assertion $$\mathbf{A}$$ and the other is labelled as Reason $$\mathbf{R}$$ :

Assertion A : The first ionisation enthalpy decreases across a period.

Reason $$\mathbf{R}$$ : The increasing nuclear charge outweighs the shielding across the period.

In the light of the above statements, choose the most appropriate from the options given below :

$$\mathbf{A}$$ is false but $$\mathbf{R}$$ is true

Both $$\mathbf{A}$$ and $$\mathbf{R}$$ are true but $$\mathbf{R}$$ is NOT the correct explanation of $$\mathbf{A}$$

Both $$\mathbf{A}$$ and $$\mathbf{R}$$ are true and $$\mathbf{R}$$ is the correct explanation of $$\mathbf{A}$$

$$\mathbf{A}$$ is true but $$\mathbf{R}$$ is false

First ionisation energy increases along the period. Along the period $$\mathrm{Z}$$ increases which outweighs the shielding effect.