Electron configuration notation details how electrons are distributed among an atom's orbitals. This information is crucial for predicting chemical reactivity and properties, rather than detailing nuclear composition.

Hydrogen has only one electron, and in its ground state it occupies the lowest energy orbital, which is 1s. This simple configuration is a key example of electron arrangement for single-electron atoms.

The Aufbau Principle guides the order in which electrons occupy orbitals, starting from the lowest-energy level and moving upward. This systematic filling is a cornerstone for understanding electron configurations.

An s orbital has a spherical shape and can accommodate up to 2 electrons. In contrast, p orbitals can hold 6 electrons, d orbitals 10 electrons, and f orbitals 14 electrons.

Lithium has three electrons; two fill the 1s orbital and the remaining electron occupies the 2s orbital. This leads to the configuration 1s2 2s1, following the Aufbau Principle.

A p subshell consists of three orbitals, and since each orbital can hold 2 electrons, the total capacity is 6. This fact is essential when determining electron distributions in elements.

Sodium has 11 electrons; using the noble gas shorthand, the first 10 electrons are represented by [Ne] (the configuration of neon), followed by a single electron in the 3s orbital. This concise representation simplifies the writing of electron configurations.

Hund's Rule states that electrons will singly occupy degenerate orbitals with parallel spins to minimize repulsion before any pairing occurs. This results in a more stable electron configuration.

Once the 4s orbital is filled, the 3d orbital is next in line due to its lower energy compared to the 4p orbital. This ordering is particularly important for understanding the electron configurations of transition metals.

The d subshell comprises five orbitals, each of which can hold 2 electrons, resulting in a total capacity of 10 electrons. This concept is fundamental when determining the configurations of transition elements.

Oxygen, with 8 electrons, fills the 1s and 2s orbitals completely before partially filling the 2p orbital, leading to the configuration 1s2 2s2 2p4. This obeys both the Aufbau Principle and the Pauli Exclusion Principle.

The notation [Ar] is used as a shorthand to represent argon's full electron configuration, thereby simplifying the electron configuration of larger atoms. It signifies that the inner electrons match those of argon.

According to the Aufbau Principle, the 4s orbital should be filled before the 3d orbital. The configuration that fills 3d10 before 4s2 does not follow the correct order and is therefore incorrect.

The principal quantum number (n) directly indicates the energy level or shell that an electron occupies, reflecting its average distance from the nucleus. This number is fundamental in determining the overall energy associated with an electron.

The Pauli Exclusion Principle ensures that each electron in an atom is characterized by a unique set of four quantum numbers. This rule is essential for understanding electron arrangement and avoiding duplicate electron states.

The notation '4p' indicates that the electrons in question are in the fourth energy level. Therefore, an element with electrons in the 4p subshell belongs to period 4 of the periodic table.

Transition metals often exhibit configurations that differ from simple predictions because electron-electron repulsions and specific energy stabilization effects can alter orbital energies. Such deviations are observable in elements like copper and chromium.

Chromium adopts an electron configuration of [Ar] 4s1 3d5 to achieve a half-filled d subshell, which confers extra stability. This anomaly deviates from the expected Aufbau order but is well documented in chemical literature.

Electron shielding occurs when inner electrons partially block the positive charge of the nucleus, reducing the effective nuclear charge on outer electrons. This effect influences orbital energies and explains periodic trends in atomic properties.

For electrons in a p orbital, the angular momentum quantum number l is 1, which gives rise to three possible magnetic quantum numbers: -1, 0, and +1. This information is crucial for understanding the spatial orientation of p orbitals.