Pauli exclusion principle

This term refers to a fundamental law of quantum mechanics that governs the behavior of fermions, such as electrons. It is the reason why matter has volume and stability; without it, electrons would collapse into the lowest energy state, making the complex structure of atoms and the periodic table impossible.

In academic and scientific discourse, the term is used as a proper noun phrase. Because it describes a singular, universal law of physics, it is treated as an uncountable concept and does not have a plural form in standard scientific usage.