S-orbital

Definition

An s-orbital is a spherical region in an atom where there is a high probability of finding an electron. This type of orbital is defined by its quantum number and has unique characteristics that relate to the arrangement of electrons in multi-electron atoms, the values of quantum numbers, and how these orbitals contribute to the electron configurations of elements in the periodic table.

5 Must Know Facts For Your Next Test

1. The s-orbital can hold a maximum of 2 electrons, which must have opposite spins according to the Pauli exclusion principle.
2. All s-orbitals have a spherical shape, and their size increases as the principal quantum number increases.
3. In multi-electron atoms, s-orbitals are filled before p-orbitals according to the Aufbau principle.
4. The first shell (n=1) contains only one s-orbital, while higher shells contain both s and p orbitals.
5. The energy levels of s-orbitals are lower than those of p, d, or f orbitals within the same principal energy level.

Review Questions

• How does the s-orbital relate to the Pauli exclusion principle in multi-electron atoms?
  • The s-orbital, like all orbitals, is subject to the Pauli exclusion principle, which states that no two electrons can occupy the same quantum state simultaneously. This means that in any given s-orbital, there can only be a maximum of two electrons, each with opposite spins. In multi-electron atoms, this principle ensures that electrons fill the lowest energy orbitals first while obeying these occupancy rules, impacting how they interact and bond with other atoms.
• Discuss the role of quantum numbers in determining the properties of s-orbitals and how they affect electron configuration.
  • Quantum numbers define specific properties of s-orbitals such as their shape and size. The principal quantum number (n) indicates the energy level and size of the orbital. For s-orbitals, l equals 0, which signifies a spherical shape. This arrangement directly impacts electron configuration since electrons fill lower-energy s-orbitals before moving on to p or d orbitals. Understanding these quantum numbers is crucial for predicting how atoms will behave during chemical reactions.
• Evaluate how the characteristics of s-orbitals contribute to trends in the periodic table and chemical bonding.
  • S-orbitals play a significant role in determining chemical properties and trends within the periodic table. Since elements in Group 1 and Group 2 have their outermost electrons in s-orbitals, this affects their reactivity and bonding characteristics. For example, alkali metals with a single electron in their outermost s-orbital are highly reactive. Moreover, as you move down a group, the increasing size of s-orbitals affects ionization energy and electronegativity trends. Understanding these relationships helps predict how elements will interact with one another.

Related terms

Quantum Number: A number that describes the properties of atomic orbitals and the electrons in those orbitals, including their energy level and shape.

Electron Configuration: The distribution of electrons among the various orbitals in an atom, which follows specific rules based on the energy levels of the orbitals.

Pauli Exclusion Principle: A principle stating that no two electrons in an atom can have the same set of four quantum numbers, leading to specific occupancy rules for orbitals.