Atomic Structure and Quantum Numbers

Flashcards summarizing key concepts related to atomic structure and quantum numbers from lecture notes.

Electron Configuration

The distribution of electrons in different energy levels and sublevels within an atom.

Pauli Exclusion Principle

No two electrons in the same atom can have the same four quantum numbers, so an atomic orbital can hold a maximum of two electrons with opposite spins.

Hund's Rule

Electrons will occupy degenerate orbitals singly before any orbital is doubly occupied, and the single electrons in degenerate orbitals will have parallel spins.

Aufbau Principle

Electrons fill atomic orbitals in order of increasing energy.

Principal Quantum Number (n)

Indicates the principal energy level of an electron; can be any positive integer.

Azimuthal Quantum Number (l)

Describes the shape of the orbital and can take on integer values from 0 to n-1.

Magnetic Quantum Number (ml)

Specifies the orientation of the orbital in space, taking integer values from -l to +l.

Spin Quantum Number (ms)

Describes the intrinsic angular momentum of the electron; can be +1/2 or -1/2.

Cations

Positively charged ions formed when an atom loses electrons, removing from the highest energy orbitals first.

Anions

Negatively charged ions formed when an atom gains electrons, adding them to the lowest energy orbitals available.

Electron Configuration of Chromium (Cr)

[Ar] 3d5 4s1, deviating from the Aufbau principle to maximize stability.

Electron Configuration Stability Rule

Complete sublevels and half-filled sublevels are more stable due to symmetry in electron distribution.

Why Zinc is not a Transition Element

Zinc's 3d sublevel is fully filled (3d10) in both its neutral and common ion state.

Quantum Numbers for electrons in a 4p sublevel

n=4, l=1, ml=-1, 0, +1, ms=±1/2.

Effect of External Magnetic Field on Quantum Numbers

The magnetic quantum numbers (ml) split into different energy levels (Zeeman effect).