The ground state electron configuration describes how electrons are distributed among the various atomic orbitals, following the Aufbau principle, which dictates that electrons fill lower energy orbitals before occupying higher ones. The term "Aufbau" translates to "build up" in German, reflecting this foundational concept in electron arrangement.

To express electron configurations more efficiently, we use condensed electron configurations. This method involves starting from the last noble gas preceding the element in question, which simplifies the notation significantly. The periodic table is divided into blocks: the s block, p block, d block, and f block. In organic chemistry, the focus is primarily on nonmetals, so the d and f blocks are generally less relevant.

For example, let's consider the element phosphorus, which has an atomic number (Z) of 15, indicating it has 15 electrons. Following the Aufbau principle, we can derive its ground state electron configuration by filling the orbitals in order:

1s² 2s² 2p⁶ 3s² 3p³.

This configuration shows that the 1s orbital is filled with 2 electrons, the 2s with 2, the 2p with 6, the 3s with 2, and finally, the 3p with 3 electrons, totaling 15 electrons, which matches the atomic number of phosphorus.

For the condensed electron configuration, we identify the last noble gas before phosphorus, which is neon. Thus, the condensed configuration is represented as:

[Ne] 3s² 3p³.

This notation succinctly captures the electron distribution for phosphorus, highlighting both the ground state and condensed configurations effectively.