Chemistry: Atomic Theory Scientists - First Half

Democritus and Leucippius

Had a mentor and student relationship; claimed that matter is composed of small, indivisible parts called atoms (atomos). Said they could not be created or destroyed, but are always changing.

Empedolces

Wrote "On Nature" and "The Purification." Believed in the "Four Roots" (water, earth, fire, air) and said that love unites and attracts elements while strife separates them.

Aristotle

Said that all matter is continuous and deprived from the 4 elements. Also said change occurs through matter shifting from its potential state to an actual state.

Atomists

What were Democritus and Leucippius called?

Elementalists

What were Aristotle and Empedolces called?

Lavoisier

Shifted chemistry from a qualitative study of alchemical elements into a quantitative physical science; proposed the Law of Conservation of Mass (matter cannot be created or destroyed, only changed); established fundamental laws for chemistry

Hennig Brand

Discovered phosphorus and laid the ground work for atomic theory

Micheal Faraday

Laid the foundations for the modern electrical age, discovered electromagnetic induction, electric and magnetic forces operate through the continuous physical fields and "lines of force"

Joesph Proust

Created the Law of Definite Proportions; compounds always contain elements in fixed whole number proportions

Robert Boyle

Father of Chemistry; replaced philosophy with experimentation and proposed corpuscles

John Dalton

Helped develop modern atomic theory, using the Billard Ball Model. Said that all matter is made up of tiny, indivisible, homogeneous, and indestructible particles called atoms. His theory supported Proust, Democritus, and Lavoisier.

Jöns Jacob Berzelius

Discovered multiple elements. determined precise atomic weights, invented chemical notation, and changed a universal language for chemistry. Claimed that every chemical compound consists of two electrically opposite parts

Amedeo Avogardo

Proposed law which states that equal volume of all gases at the same temp and pressure contain the same number of molecules.

Joesph Louis Gay-Lussac

Combined volumes of gasses

Henry Cavendish

Elemental Theory; discovered hydrogen gas and the density and mass of Earth, proved water was a chemical compound