DEMOCRITUS AND JOHN DALTON

DEMOCRITUS

• Made contribution in 465 BC
• Discovered it by expanding on his mentors theory

DISCOVERY

• Claimed everything was made up of atoms
• What is thought to be the first atomic theory
• Still influences what we know today

JOHN DALTON

• Made discovery in the early 1800s
• Discovered through his research of gases, deductive reasoning, and experimentation

DISCOVERY

• All matter is made up of atoms
• All atoms of a given element are identical in mass and properties
• Essence of his theory still remains valid

NEILS BOHR

• Made discovery during 1912-1962
• Made discovery through working with Ernest Rutherford

DISCOVERY

• Explains what happens inside an atom
• Developed picture of atomic structure
• Concepts formed basis of quantum theory