S orbital

Definition

An s orbital is a type of atomic orbital that is spherical in shape and can hold a maximum of two electrons with opposite spins. It represents the lowest energy level in any given principal quantum number and plays a crucial role in the structure of atoms and the arrangement of electrons around the nucleus.

5 Must Know Facts For Your Next Test

1. The s orbital can exist in different energy levels corresponding to different principal quantum numbers (n = 1, 2, 3, ...), with each energy level having one s orbital.
2. The shape of the s orbital remains consistent regardless of its energy level, always maintaining a spherical symmetry around the nucleus.
3. In multi-electron atoms, the s orbitals are filled before the higher-energy p, d, and f orbitals due to their lower energy state.
4. The first electron shell (n=1) contains only one s orbital, while the second shell (n=2) contains one 2s orbital as well as three p orbitals.
5. In terms of energy, the s orbitals are generally lower in energy than p, d, and f orbitals at the same principal quantum number.

Review Questions

• How do s orbitals differ from other types of atomic orbitals in terms of shape and electron capacity?
  • S orbitals are unique because they have a spherical shape, unlike p orbitals that have a dumbbell shape. Each s orbital can hold up to two electrons with opposite spins, which is a common feature among all atomic orbitals. However, the defining characteristic of s orbitals is their lower energy level compared to p, d, and f orbitals at the same principal quantum number.
• Discuss how the arrangement of electrons in s orbitals affects an atom's overall electron configuration.
  • The arrangement of electrons in s orbitals significantly influences an atom's electron configuration by determining how electrons fill available energy levels. Since s orbitals are filled first due to their lower energy state, they establish a foundational layer for additional electron filling in p, d, and f orbitals. This initial filling pattern affects chemical reactivity and bonding characteristics of elements.
• Evaluate the implications of the Pauli Exclusion Principle on the filling of s orbitals within multi-electron atoms.
  • The Pauli Exclusion Principle ensures that no two electrons can occupy the same quantum state within an atom. This principle means that when filling s orbitals in multi-electron atoms, each orbital can contain a maximum of two electrons with opposite spins. Consequently, this restriction influences how electrons fill available energy levels and contributes to the overall stability and chemical behavior of the atom.

Related terms

Principal Quantum Number: A number (n) that indicates the main energy level occupied by an electron, where higher values correspond to greater distances from the nucleus.

Electron Configuration: The distribution of electrons in an atom's orbitals, following the rules of quantum mechanics, which determines the chemical properties of elements.

Pauli Exclusion Principle: A principle stating that no two electrons in an atom can have the same set of four quantum numbers, meaning each electron in an orbital must have a unique spin.