Solution:
To answer this question, let's first analyze the Assertion (A) and the Reason (R) separately and then relate them.
Analysis of Assertion (A):
The assertion states that the molecular orbitals π(2px),π(2py),π*(2px),π*(2py) all have one nodal plane each. The molecular orbitals formed by the combination of p atomic orbitals in a sideways manner are indeed termed as π and π* orbitals. Specifically, π orbitals are bonding molecular orbitals with no nodal planes through the bonding region, whereas π* orbitals are antibonding molecular orbitals with one nodal plane through the bonding region. Thus, π orbitals should ideally have no nodal planes through the bonding region, and π* orbitals should have one. Therefore, the assertion that all the mentioned orbitals, including the π orbitals, have one nodal plane each is incorrect.
Analysis of Reason (R):
The reason given states that all molecular orbitals formed by the sideways overlapping have one nodal plane. This is a generalized statement that is not fully accurate. The π molecular orbitals, formed by sideways overlap of unhybridized p orbitals, typically have no nodal planes through the bonding region (areas between the nuclei involved in bonding), whereas π* orbitals, which are antibonding, do have such a nodal plane. Thus, the reason is overly generalized and misleading.
Conclusion:
Given the incorrect statement in both the assertion and the reason, and the incorrect association between them, the correct option is:
Option B: Both assertion and reason are false.
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