Spin quantum number

Definition

The spin quantum number ($m_s$) describes the intrinsic angular momentum (spin) of an electron in an atom. It can have a value of either +½ or -½, representing the two possible orientations of an electron's spin.

5 Must Know Facts For Your Next Test

1. The spin quantum number is denoted by $m_s$.
2. $m_s$ can only take on values of +½ or -½.
3. It is necessary for describing the unique state of an electron within an atom along with three other quantum numbers: $n$, $l$, and $m_l$.
4. It accounts for the magnetic properties of electrons due to their spin.
5. The Pauli Exclusion Principle states that no two electrons in the same atom can have identical sets of all four quantum numbers.

Review Questions

• What are the possible values for the spin quantum number?
• How does the Pauli Exclusion Principle relate to the spin quantum number?
• Why is the spin quantum number important in determining an electron's state?

Related terms

Principal Quantum Number (n): Describes the main energy level or shell occupied by an electron.

Azimuthal Quantum Number (l): Defines the shape of an orbital and is also known as the angular momentum quantum number.

Magnetic Quantum Number (m_l): Specifies the orientation of an orbital around the nucleus.