Development of the atomic theory

Periodic Table

A representation of all elements that man has encountered throughout time.

Dmitri Mendeleev

A Russian chemist who created the periodic table in 1869, recognizing that its arrangement reflects the properties of elements.

Robert Boyle

A chemist who criticized alchemy, supporting the corpuscular theory that matter is composed of minute particles.

Corpuscles

Primitive and simple indivisible bodies of matter proposed by Robert Boyle.

Mechanical Philosophy

An experimental approach suggested by Robert Boyle, emphasizing observation and testing.

Element

The simplest unit of substances that cannot be simplified or decomposed through chemical reactions.

Antoine Lavoisier

Scientist who demonstrated the Law of Conservation of Mass and identified 33 elements, writing the first chemistry textbook.

Phlogiston Theory

The theory suggesting that combustion releases a fire-like element called phlogiston.

Johann Becher

Scientist associated with the phlogiston theory.

Phlogiston

A fire-like element postulated by the phlogiston theory.

Democritus

Philosopher who developed the concept of atomism.

John Dalton

Scientist who published his atomic theory in 1808, which includes the law of definite proportion and law of multiple proportions.

Joseph Gay-Lussac

Scientist who proposed that oxygen exists in molecular form rather than as a single free atom.

Amedeo Avogadro

Scientist who determined that the masses of atoms and molecules can be calculated through gases.

Period

The horizontal alignment of elements in the periodic table.

Group

The vertical alignment of elements in the periodic table.