Can you name one thing that easily distinguishes you from the rest of the world?
And we’re not talking about DNA – that’s a little expensive to sequence. For many people, it is their email address. My email address allows people all over the world to contact me. It does not belong to anyone else, but serves to identify me. Electrons also have a unique set of identifiers in the quantum numbers that describe their location and spin.
Pauli Exclusion Principle
When we look at the orbital possibilities for a given atom, we see that there are different arrangements of electrons for each different type of atom. Since each electron must maintain its unique identity, we intuitively sense that the four quantum numbers for any given electron must not match up exactly with the four quantum numbers for any other electron in that atom.
- The Pauli exclusion principle specifies limits on how identical quantum numbers can be for two electrons in the same atom.
- What is the difference between the two helium electrons?
- What does the Pauli exclusion principle state?
- What does the two values for the spin quantum number allow?