Which electronic configuration for p-orbitals obeys all the rules Pauli Exclusion Principle; Hund’s Rule and Aufbau Principle)? (a) 0 1 1 (b) 4 _ – (c) L 1 1 (d) 1 4 1 Select one: Only d b. All of them Only Your answer is incorrect Only Only
The Correct Answer and Explanation is:
The correct answer is: (a) 0 1 1
Explanation:
To determine which p-orbital electron configuration obeys all three fundamental rules — the Aufbau Principle, Pauli Exclusion Principle, and Hund’s Rule — we need to evaluate each choice carefully.
1. Understanding the p-Orbitals
- A p-subshell has three orbitals: pxp_xpx, pyp_ypy, and pzp_zpz
- Each orbital can hold a maximum of two electrons with opposite spins
- So the p-subshell can hold up to six electrons total
2. The Three Principles
- Aufbau Principle: Electrons fill orbitals in order of increasing energy. Lower energy orbitals fill before higher ones.
- Pauli Exclusion Principle: No two electrons in the same atom can have the same set of four quantum numbers. Therefore, each orbital can have at most two electrons, and they must have opposite spins.
- Hund’s Rule: When electrons occupy orbitals of equal energy (degenerate orbitals), one electron enters each orbital until all are half-filled before pairing begins. Electrons in singly occupied orbitals will have parallel spins.
3. Evaluate the Options
- (a) 0 1 1
This means one electron in each of two orbitals and none in the third. This follows:- Hund’s Rule: Yes, electrons occupy separate orbitals before pairing.
- Pauli Exclusion Principle: Yes, since no orbital has more than one electron.
- Aufbau Principle: Yes, electrons are filling the lowest energy p-orbitals.
✓ This is correct.
- (b) 4 _ –
Invalid. No orbital can have 4 electrons. This violates both Pauli Exclusion Principle and Aufbau Principle.
✗ Incorrect. - (c) L 1 1
This is not a valid numeric configuration. ‘L’ is not a number, so it’s ambiguous or invalid.
✗ Incorrect. - (d) 1 4 1
The second orbital has 4 electrons, which is impossible.
✗ Incorrect.
Conclusion:
Only option (a) 0 1 1 satisfies all three rules of electronic configuration.
