EVOLUTION OF THE ATOMIC THEORY

B y: Dev Patel and Arnold Hernandez

Aristotle/Democritus (Ancient Philosophy) Who- Aristotle and Democritus When-More than 2,000 years ago Where-Greece What-Aristotle believed in four elements:

Earth, Air, Fire, and Water. Democirtus believed that matter was made of small particles he named “atoms.”

Why-Aristotle and Democritus used observation and inference to explain the existence of everything.

Alchemists(Ancient Philosophy)

Who-Alchemists(European Scientist) When-800-900 years ago Where-Europe What-Their work developed into what is

now modern chemistry. Why-Trying to change ordinary materials

into gold

John Dalton(Atomic Particle Theory) Who-John Dalton When-1808 Where-England What-Describe atoms as tiny particles

that could not be divided. Thought each element was made of its own kind of atom. Developed the “Atomic Theory”

Why-Building on the ideas of Democritus in ancient Greece.

Dalton’s Atomic Theory

Elements are composed of small indivisible particles.(atoms)

Atoms of the same element are identical. Atoms of different elements are different.

Atoms of different elements combine together in simple proportions to create compounds.

In a chemical reaction, atoms are rearranged not changed.