# The Pauli Exclusion Principle, Real Time Examples and Some Exception.

The Pauli Exclusion Principle states that no two electrons in an atom can have the same set of four quantum numbers. The four quantum numbers are:

• Principal quantum number (n): This tells us the energy level of the electron.
• Azimuthal quantum number (l): This tells us the shape of the orbital.
• Magnetic quantum number (ml): This tells us the orientation of the orbital.
• Spin quantum number (ms): This tells us the spin of the electron, which can be either +1/2 or -1/2.
Contents

## What is the Pauli Exclusion Principle?

The Pauli Exclusion Principle states that no two electrons in an atom can have the same set of four quantum numbers. The four quantum numbers are:

Wolfgang Pauli was an Austrian physicist who formulated the Pauli Exclusion Principle in 1925.

According to the Pauli Exclusion Principle, two electrons can only have the same values for the first three quantum numbers (n, l, and ml) if their spin quantum numbers are different. This means that no two electrons in an atom can have the same energy, orbital, and spin. This is because electrons are fermions, which are particles that obey the Pauli Exclusion Principle.

For example, the two electrons in the 1s orbital of a hydrogen atom must have opposite spins. This is because they both have the same values for the first three quantum numbers (n = 1, l = 0, and ml = 0). However, they can have different spin quantum numbers (ms = +1/2 and ms = -1/2).

The said Principle is responsible for the fact that electrons in an atom are arranged in different orbitals. If two electrons could have the same set of quantum numbers, they would both collapse into the same orbital, which is not possible.

It has also implications for the properties of matter. For example, it is responsible for the fact that atoms cannot be squeezed too closely together. If two atoms were to be squeezed too closely together, their electrons would start to occupy the same orbitals, which would violate the Pauli Exclusion Principle.

The said Principle is one of the most important principles in quantum mechanics. It has a profound impact on the properties of matter and the structure of atoms.

## Some Real Time Examples of the Pauli Exclusion Principle:

Here are some examples of how the said Principle applies to real-world phenomena:

1.The Pauli Exclusion Principle is responsible for the fact that matter has volume. If electrons could all occupy the same orbital, atoms would collapse into a point and have no volume.

2.The Pauli Exclusion Principle is responsible for the fact that atoms cannot be chemically combined in all possible ways. For example, two hydrogen atoms cannot share the same electron orbital, so they can only form a molecule if they share electrons in different orbitals.

3.The Pauli Exclusion Principle is responsible for the fact that metals are good conductors of electricity. Electrons in metals can move freely from atom to atom because they are not restricted to any one orbital.

## Deviation in the Pauli Exclusion Principle?

1. The Pauli Exclusion Principle has never been observed to be violated. However, there are some situations where it seems like it could be violated. For example, in a system of very cold fermions, the Pauli Exclusion Principle can be overcome by the effects of quantum tunneling. This is called the BEC-BCS crossover.

2. Another situation where the Pauli Exclusion Principle seems like it could be violated is in the case of a neutron star. Neutron stars are very dense stars that are made up of neutrons. It would seem to prevent neutrons from being packed too tightly together. However, the gravity of the neutron star is so strong that it can overcome the Pauli Exclusion Principle.

## Conclusion:

The Pauli Exclusion Principle says that no two electrons in an atom can have the same four quantum numbers. This means that no two electrons can have the same energy, spin, and orbital. The principle is responsible for the stability of atoms and molecules. However, some deviations are also found in extreme condition.