Aufbau Principle: This principle states that electrons fill up the lowest energy levels first before moving on to higher ones. It's like filling up the front rows at a concert before letting people into the back rows.
Pauli Exclusion Principle: This principle says that no two electrons can have identical quantum states. Imagine it as each person having their own unique seat at the wedding; no two people can sit in exactly the same spot!
Hund's Rule: Hund's rule states that every orbital in a subshell is singly occupied with one electron before any one orbital is doubly occupied. It’s like ensuring each room in a house has one occupant before anyone gets a roommate!