Atomic Models and Quantum Mechanics

These flashcards cover key concepts related to atomic models, quantum mechanics, quantum numbers, electron configurations, photoelectron spectroscopy, periodic table organization, and trends.

Dalton's Atomic Theory

Atoms are indivisible, indestructible, and of a given element are identical, combining in simple whole-number ratios to form compounds.

Thomson's Plum Pudding Model

A model proposing that atoms are spheres of positive charge with electrons embedded in them.

Rutherford's Gold Foil Experiment

Revealed the presence of a positively charged nucleus in atoms and that they are mostly empty space.

Bohr Model

Model stating that electrons orbit the nucleus in specific energy levels, with transitions involving energy absorption or emission.

Quantum Mechanical Model

Describes electrons as wave-particle dual entities, relying on the Heisenberg Uncertainty Principle.

Wave-Particle Duality

Concept where particles, including electrons, can exhibit both wave-like and particle-like properties.

Heisenberg Uncertainty Principle

It is impossible to simultaneously know the exact position and momentum of an electron.

Schrödinger Equation

A mathematical equation that describes the behavior of electrons in atoms using wave functions.

Principal Quantum Number (n)

Indicates the main energy level of an electron in an atom, with higher values signifying greater energy and distance from the nucleus.

Angular Momentum Quantum Number (l)

Describes the shape of an orbital, with values ranging from 0 to n-1.

Magnetic Quantum Number (m_l)

Describes the orientation of an orbital in space, with defined values for different types of orbitals.

Spin Quantum Number (m_s)

Describes the intrinsic spin of an electron, with possible values of +1/2 or -1/2.

Aufbau Principle

Electrons fill the lowest energy orbitals before filling higher ones.

Pauli Exclusion Principle

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

Hund's Rule

Electrons will singly occupy degenerate orbitals before pairing up.

Noble Gas Configuration

A shorthand notation for electron configuration using the symbol of the nearest noble gas.

Photoelectron Spectroscopy (PES)

Technique that provides evidence for electron shell structure and measures ionization energies by observing ejected electrons.

Periodic Table Organization

Arranged by electron configuration and recurring chemical properties among elements.

Atomic Radius Trend

Decreases across a period due to increasing nuclear charge pulling valence electrons closer to the nucleus.