Understanding Electron Configuration
* Atomic Number: Sodium has an atomic number of 11, meaning it has 11 protons and 11 electrons.
* Energy Levels: Electrons occupy specific energy levels around the nucleus. These levels are designated as 1, 2, 3, and so on, with higher numbers indicating higher energy.
* Sublevels: Each energy level is divided into sublevels (s, p, d, f), which also have varying energy levels within a given level.
Sodium's Electron Configuration
1. First Energy Level (n=1): It can hold a maximum of 2 electrons (in the 's' sublevel). So, sodium's first two electrons fill this level.
2. Second Energy Level (n=2): This level has 's' and 'p' sublevels. The 's' sublevel holds 2 electrons, and the 'p' sublevel holds 6 electrons (for a total of 8). Sodium's next 8 electrons fill this level.
3. Third Energy Level (n=3): The 11th electron goes into the 's' sublevel of the third energy level.
Why Not the Second Energy Level?
The second energy level can hold a maximum of 8 electrons. Sodium already has 8 electrons in the second level. To accommodate the 11th electron, the next available energy level is the third one.
Key Point: Electrons fill energy levels and sublevels in a specific order, following the Aufbau principle. This principle states that electrons occupy the lowest available energy levels first.
