Which of the following describes the electronic configuration of sodium?

The electronic configuration of sodium is represented as 2, 8, 1. This configuration reflects the distribution of electrons in the various energy levels around the nucleus of a sodium atom.

Sodium has an atomic number of 11, meaning it has 11 electrons. The first energy level can hold a maximum of 2 electrons, which accounts for the first part of the configuration: 2. The second energy level can hold up to 8 electrons, leading to the next part being 8. Finally, sodium has 1 electron in the third energy level, resulting in the last part being 1.

Combining these, the complete electronic configuration of sodium is effectively described as 2 (for the first level), 8 (for the second level), and 1 (for the third level). This configuration not only shows how electrons are organized in sodium but also elucidates why sodium has a particularly reactive nature, as the single electron in its outermost shell makes it prone to losing that electron and forming positive ions.