Atomic Structure Models to Know (AP Chemistry)

Atomic Structure Models

Dalton's Atomic Theory

The first formal description of atoms, proposing they are indivisible particles that make up matter.

Indivisibility of Atoms

Dalton's principle that atoms cannot be split into smaller parts.

Elemental Identity

Atoms of a specific element are identical in mass and properties.

Conservation in Reactions

In chemical reactions, atoms are rearranged but neither created nor destroyed.

Thomson's Plum Pudding Model

A model suggesting that atoms consist of electrons in a positive matrix.

Subatomic Particles

Particles smaller than atoms, introduced by Thomson's model.

Rutherford's Nuclear Model

A model showing that atoms have a dense nucleus around which electrons orbit.

Nucleus Discovery

Rutherford's finding that atoms contain a small, dense, positively charged nucleus.

Planetary Model

A model depicting electrons orbiting the nucleus like planets around the sun.

Bohr's Atomic Model

A model introducing fixed paths for electrons around the nucleus.

Fixed Electron Orbits

Electrons in Bohr's model occupy specific, quantized paths.

Energy Absorption and Emission

Electrons absorb energy to move to a higher level and release energy when falling back.

Quantum Mechanical Model

A model describing electrons as probabilistic clouds around the nucleus.

Wave-Particle Duality

The concept that electrons exhibit both wave-like and particle-like properties.

Atomic Orbitals

Regions in space where electrons are likely to be found, differing in shape and size.

Complex Math of Quantum Mechanics

Mathematical equations used to predict electron positions probabilistically.

Schrödinger's Wave Model

Model that uses wave functions to describe electron behavior as probability distributions.

Wave Equation

An equation developed by Schrödinger to describe the behavior of electrons.

Electron Probability Distributions

Regions where there is a higher likelihood of finding electrons.

Dual Nature of Electrons

The principle emphasizing that electrons have both wave and particle characteristics.

Limitations of Dalton's Theory

Ignored subatomic particles and treated atoms as indivisible.

Limitations of Thomson's Model

Incorrectly predicted how electrons were distributed within the atom.

Limitations of Rutherford's Model

Did not account for defined energy levels of electrons.

Limitations of Bohr's Model

Only accurate for hydrogen atoms.

Limitations of Quantum Mechanical Model

Requires complex mathematics to understand.

Limitations of Schrödinger's Wave Model

Requires advanced math and is more abstract.

Chemical Reactions

Processes in which atoms rearrange to form new substances.

Law of Conservation of Mass

Mass is neither created nor destroyed in chemical reactions.

Niels Bohr

A physicist who expanded on Rutherford's model by introducing quantized energy levels.

J.J. Thomson

A physicist known for discovering the electron and proposing the plum pudding model.

Ernest Rutherford

A physicist who conducted the gold foil experiment leading to the nuclear model of the atom.

John Dalton

The scientist who first described atoms as indivisible and fundamental building blocks of matter.

Electron Cloud Model

Another name for the quantum mechanical model describing probabilities of electron locations.

Emission Spectrum

The spectrum of light emitted by electrons transitioning between energy levels.