Science Common Sense

1720 - What are the rules for filling atomic electron configurations, including the Pauli Exclusion Principle, Hund's Rule, and the Aufbau Principle?

Imagine building a big building with rooms (orbits). Here are the rules to fill the rooms with people (electrons):

  1. Aufbau Principle (Building Up Rule): Start with the ground floor (1st orbit). Fill it before moving to the next floor (2nd orbit), and so on. Each floor has a maximum number of rooms.

  2. Pauli Exclusion Principle (Pair Up Rule): No two people (electrons) can have the same "identity card" (energy, spin, and orbitals). This means no more than 2 people can live in the same room, but they must have opposite spins (clockwise and anticlockwise).

  3. Hund's Rule (Spread Out Rule): If there are many empty rooms on the same floor (orbitals with the same energy), fill them one person at a time before pairing up. This helps keep the people (electrons) happy by spreading them out.

These rules help us fill the atomic building and create a map of electron configurations, which are important for understanding chemistry.

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