Atomic Theory Flashcards

Flashcards on Atomic Theory

Democritus

Proposed the idea of atomos, indivisible units that make up matter, which means uncuttable or indivisible.

Law of Conservation of Matter

Matter cannot be created or destroyed, only changed.

Aristotle

Did not believe in atoms; thought matter was composed of earth, air, fire, and water.

John Dalton

Proposed the Solid Sphere Model in the early 1800s and created the law of partial pressures.

Solid Sphere Model

Atoms are indivisible and indestructible.

J.J. Thomson

Proposed the Plum Pudding Model and discovered electrons, leading to a shift in the understanding of atomic structure.

Plum Pudding Model

Atoms are a positively charged substance with negatively charged electrons scattered throughout.

Rutherford

Created the Nuclear Model through the gold foil experiment.

Gold Foil Experiment

Alpha particles were shot at a thin gold foil, and their deflection patterns led to the discovery of the nucleus.

Nuclear Model

Atoms have a small, dense, positively charged nucleus surrounded by mostly empty space.

Bohr

Proposed the Planetary Model in the early 20th century and introduced the concept of energy levels.

Planetary Model

Electrons orbit the nucleus in specific energy levels or shells.

Chadwick

Discovered the neutron.

Schrödinger

Proposed the Quantum Model, which is the foundation of the modern atomic model.

Quantum Model

Electrons are found in probability regions called orbitals, not in fixed paths.

Modern Atomic Model

Electrons are found in electron clouds or orbitals, regions of probability surrounding the nucleus.