Question

Name the principle, which says an orbital can hold only 2 electrons.

Answer 1

According to Pauli’s exclusion principle, an s orbital contains at most two electrons with the opposite spin (up and down).

Answer 2

Pauli Exclusion Principle

This principle states that every electron should be in its own unique state. That means no electrons in an atom are allowed to have an identical set of quantum numbers. This principle helps to explain the arrangement of electrons in atoms and molecules and to rationalize the patterns in the periodic table. The principle is applicable only to fermions, for example, protons, neutrons and electrons. It is not applicable to bosons, for example, a photon - light beam.

The Austrian physicist Wolfgang Pauli received the Nobel Prize in Physics in 1945 for his discovery related to electrons.