Indicate which of the following electron configurations are...

Indicate which of the following electron configurations are ruled out by the Pauli exclusion principle:
(a) $1 s^{2} 2 s^{2} 2 p^{7}$
(b) $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{3}$
(c) $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{2} 3 d^{12}$
(d) $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6}$

Key Concepts

Electron Configuration

Electron configuration is the arrangement of electrons in the atomic orbitals of an atom. It not only describes how electrons fill available orbitals in order of increasing energy but also is expressed using a notation that indicates the orbitals (such as 1s, 2s, 2p) and the number of electrons in each orbital. This configuration is essential for understanding many chemical properties and reactivities.

Pauli Exclusion Principle

The Pauli Exclusion Principle states that no two electrons in an atom can have the same set of all four quantum numbers. This principle limits the number of electrons that can occupy a given orbital, ensuring that each orbital has a fixed maximum capacity and that electrons pair up in a way that respects this limit.

Quantum Numbers

Quantum numbers are the set of values that uniquely describe the state of an electron in an atom. They include the principal quantum number (energy level), the angular momentum quantum number (subshell type), the magnetic quantum number (orbital orientation), and the spin quantum number (electron spin). These numbers determine the arrangement of electrons in orbitals while obeying the Pauli Exclusion Principle.

Orbital/Subshell Capacity

Each type of atomic orbital has a specific maximum number of electrons it can hold, derived from the allowed combinations of quantum numbers. For instance, s orbitals can hold up to 2 electrons, p orbitals up to 6 electrons, and d orbitals up to 10 electrons. Ensuring that these limits are not exceeded is crucial for the validity of an electron configuration in accordance with the Pauli Exclusion Principle.

Transcript

Please give Ace some feedback