Understanding Quantum Mechanics and Periodic Trends

These flashcards cover key concepts related to quantum mechanics, electron configurations, atomic properties, and periodic trends, effectively summarizing important aspects to aid in exam preparation.

Quantum Numbers

A set of four numbers that describe the unique quantum state of an electron in an atom.

Principal Quantum Number (n)

Indicates the average distance of an electron from the nucleus and its energy level.

Angular Momentum Quantum Number (l)

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

Magnetic Quantum Number (m_l)

Specifies the orientation of the orbital in space and can range from -l to +l.

Spin Quantum Number (m_s)

Indicates the direction of the electron's spin, with possible values of +1/2 or -1/2.

Electron Configuration

A notation that shows the distribution of electrons among the various orbitals in an atom.

Valence Electrons

Electrons in the outermost shell of an atom that are involved in chemical bonding.

Core Electrons

Electrons that are not in the outermost shell and do not typically participate in bonding.

Ionization Energy

The amount of energy required to remove an electron from a gaseous atom or ion.

Electronegativity

A measure of the ability of an atom to attract shared electrons in a chemical bond.

Atomic Radius

The distance from the nucleus of an atom to the outermost shell of electrons.

Shielding Effect

The phenomenon where inner electrons reduce the effective nuclear charge felt by outer electrons.

Pauli Exclusion Principle

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

Hund's Rule

Electrons will occupy degenerate orbitals singly before pairing up.

Aufbau Principle

The principle that dictates the order in which orbitals are filled based on their energy levels.

Cation

A positively charged ion formed by the loss of one or more electrons.

Anion

A negatively charged ion formed by the gain of one or more electrons.

Isoelectronic

Atoms or ions that have the same electron configuration.

Noble Gas Configuration

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