Electron Configuration and Chemical Periodicity

Flashcards covering key concepts related to electron configuration, quantum numbers, periodic trends, and chemical periodicity.

Quantum Numbers

A set of four numbers that describe the unique state of an electron in an atomic orbital.

Pauli’s Exclusion Principle

No two electrons in the same atom can have the same set of four quantum numbers.

Effective Nuclear Charge (Z_eff)

The net positive charge experienced by an electron in a multi-electron atom, accounting for the shielding effect.

Aufbau Principle

Electrons occupy the lowest energy orbitals available before filling higher energy levels.

Hund’s Rule

Electrons will occupy degenerate orbitals singly with parallel spins before pairing up.

Ionization Energy (IE)

The energy required to remove an electron from an atom or ion.

Electron Affinity (EA)

The amount of energy released or spent when an electron is added to a neutral atom.

Isoelectronic

Atoms or ions that have the same number of electrons or the same electron configuration.

Paramagnetism

A property of materials that have unpaired electrons, making them attracted to a magnetic field.

Diamagnetism

A property of materials that have all paired electrons, which results in a slight repulsion from a magnetic field.

Metals

Elements that are good conductors of heat and electricity, malleable, ductile, and tend to lose electrons to form cations.

Nonmetals

Elements that tend to gain electrons, forming anions, and have higher ionization energies and electronegativities.

Valence Electrons

Electrons in the outermost shell of an atom that are involved in forming bonds.

Core Electrons

Electrons that are not involved in bonding and are located in the inner shells of an atom.

Noble Gas Configuration

An electron configuration that is similar to that of the noble gases, often achieved by gaining or losing electrons.

Metallic Behavior

A trend where elements exhibit metallic properties, like conductivity and malleability; it typically increases down a group and decreases across a period.

Acidic Oxides

Oxides formed by nonmetals that react with water to form acids.

Basic Oxides

Oxides formed by metals that react with water to form bases.

Penetration Effect

The phenomenon where some electrons can move closer to the nucleus than others, increasing nuclear attraction.

Sublevel Energy Splitting

The division of energy levels into sublevels with varying energies due to factors like penetration and shielding.

Electron Configuration

A representation of the arrangement of electrons in an atom, usually depicted by listing the occupied orbitals.

Condensed Configuration

A shorthand notation for electron configuration that uses the nearest noble gas to represent inner-core electrons.

Ionic Size vs. Atomic Size

Comparative sizes of ions and their parent atoms; cations are smaller and anions are larger than their neutral counterparts.

Inequalities in Electron Affinity Trends

The trends of electron affinity are less consistent compared to atomic size or ionization energy.

Successive Ionization Energies

The energies required to remove additional electrons from an atom after the first has been removed.

Chemical Periodicity

The recurring trends that characterize the behavior of elements in the periodic table.