HISTORY OF THE ATOM

350-450 BC

• Aristotle in350 BC came up with transmutation
• Democritus in 400 BC said matter was made of tiny particles
• Democritus called them atoms
• Empedocles in 450 BC divided matter into the four elements
• Fire,water,air, and earth and called them roots

500 BC

• The alchemists searched for the philosophers stonewhich had
• The ability to transform base materials like copper or lead into
• Valuable substances like gold.

1777-LAVOISIER

• Provided the formula for matter in chemical reactions
• Also decided between an element and a compound

1780- COULOUMB

• Made couloumbs law
• Couloumbs law states the fource between two electric charges

1803-DALTON

• Developed atomic theory
• Or as some people call it "billard ball"

1897-THOMSON

• Discovered the electron
• His theory was called "plum pudding"

1900-MAX PLANCK

• Originated the quantem theory

1905-EINSTEIN

• Said light was made of different particles with a wave like behaviour
• Made the theory of relativity

1908-ROBERT MILLIKAN

• Found the electric chargein the electron

1912-RUTHERFORD

• Discovered the nucleus
• His theory was called "sunny side up"

1913-BHOR

• Made the atomic structure we use today
• Also known as the solar system theory

1938-OTTO HAHN

• Discovered urainium fission

1938-LISE MEITHNER

• Helped otto hahn discover uranium fission

1951-GLEN.T.SEABORG

• Isolated elements heavier than uranium