I need help. In simple english please, what is Hund's Rule, Pauli Exclusion Principal, and the Aufbau Principal? I need to know these. Please try to be simple as possible because I'm not understanding right now, haha.
Thanks!! :)
Hund's rule: Electrons will occupy single orbits in different orbitals before any orbital has a pair of electrons.
ie: if you have three electrons to put in to three empty p orbitals, then one electron will go into each orbital, in no case will two go into one orbital before each orbital has at least one eletctron.
Pauli Exclusion: No electron can have the same set of quantum numbers, ie, no two electrons can occupy the same exact energy state in an atom.
Aufbau: This is a principle that says if an atom has empty electron positions, the and you start filling the available energy levels, each electron will go into the lowest energy level then currently available (remember pauli on this).
Of course! I'll explain these three principles in simple terms for you.
1. Hund's Rule: Hund's Rule states that when electrons occupy orbitals of equal energy (also known as degenerate orbitals), they will first fill each orbital with one electron before pairing up. In other words, electrons like to spread out as much as possible before being forced to pair up.
To understand this, imagine you have three rooms with equal size and amenities. According to Hund's Rule, if three people need to be accommodated, each person would prefer to have their own room first before sharing with someone else. Only when all three rooms are occupied with one person each, they would start sharing rooms. Similarly, in atoms, electrons will occupy separate orbitals with the same energy level until there is no other choice but to pair up in a shared orbital.
2. Pauli Exclusion Principle: The Pauli Exclusion Principle states that no two electrons in an atom can have the same set of quantum numbers. In simple terms, it means that each electron must be in a different state or have different properties than the others.
To understand this, imagine you have two identical toys with the same features and properties. According to the Pauli Exclusion Principle, you cannot have both of these toys in the same place at the same time. You could place one toy in one room and the other toy in a different room, but they cannot occupy the same space simultaneously. Similarly, electrons in an atom must have different properties, such as having different spins (up or down), in order to follow this principle.
3. Aufbau Principle: The Aufbau Principle states that electrons will occupy the lowest-energy orbitals first before moving to higher-energy orbitals. It describes the order in which electrons fill the various energy levels or shells of an atom.
To understand this, imagine you are building a tower of blocks. According to the Aufbau Principle, you will start by placing the first block on the ground (the lowest energy level). Once the first level is filled, you can then move upward to the next level of blocks (the next higher energy level). Similarly, electrons in an atom will occupy the lowest available energy level before moving to higher energy levels.
I hope these explanations help! Let me know if you have any further questions.