Atoms Discovery PDF

2 ATOMS DISCOVERY OF ATOMS DEMOCRITUS coined the term “atomos” matter is made up of small indivisible particles He pounded up materials in his mortar and pestle until he had reduced them to smaller and smaller particles which he called ATOMOS (indivisible) DISCOVERY OF ATOMS joh...

2 ATOMS DISCOVERY OF ATOMS DEMOCRITUS coined the term “atomos” matter is made up of small indivisible particles He pounded up materials in his mortar and pestle until he had reduced them to smaller and smaller particles which he called ATOMOS (indivisible) DISCOVERY OF ATOMS john dalton Dalton proposed a modern atomic model based on experimentation not on pure reason (Dalton’s Atomic Theory) 1. All matter is made up of atoms 2. Atoms of an element are identical 3. Each element has different atoms 4. Elements combine in definite ratios to form multiple compounds 5. Atoms cannot be created/destroyed DISCOVERY OF ATOMS john dalton Dalton proposed a modern atomic model based on experimentation not on pure reason (Dalton’s Atomic Theory) 1. All matter is made up of atoms 2. Atoms of an element are identical 3. Each element has different atoms 4. Elements combine in definite ratios to form multiple compounds 5. Atoms cannot be created/destroyed DISCOVERY OF ATOMS JJ THOMSON MODEL: RAISIN BREAD/PLUM PUDDING MODEL Negative electrons in a positive framework Found that atoms could sometimes eject (cathode-ray tube) a far smaller negative particle which is called an electron DISCOVERY OF ATOMS eugen goldstein Discovered positive rays or ions Cathode-Ray Tube generated (+) charged particles that move toward the cathode. He called it “CANAL RAYS”, formed when gaseous particles in the tube lose electrons Formed by the process: DISCOVERY OF ATOMS ernest rutherford coined the term proton proton discovery Protons are concentrated at the nucleus Discoverer of the a and b-particle Model: NUCLEAR MODEL Gold Film Experiment 99% passed through but