Lesson 3

• Democritus claimed that everything is made up of atoms and believed in the void between atoms
• Alchemy writings became more secretive and used symbols and strange names for substances to keep others from understanding their notes
• The CRT Experiment discovered electrons and their properties
• Atomism

  • Atoms make up most of the things in the universe
  • Atoms are unimaginably small and indivisible
  • Atoms are qualitatively identical, however atoms differ in shape, size, and motion
  • Movement and collision of atoms cause changes in the universe
  • Quality of atoms affects the characteristics of the things they make up
• Alchemy


  The medieval ancestor of chemistry, a form of speculative thought that tried to transform base metals such as lead or copper into silver or gold and to discover a cure for disease and a way of extending life
• Fundamental Law of Electrostatics

  Like charges repel, and opposite charges attract
• Bases of Dalton's Atomic Theory

  • Law of Conservation of Mass: Matter cannot be created nor destroyed
  • Law of Constant Composition: Regardless of the source or method of formation, a chemical compound's components are always contained in a fixed ratio
• Contributions of Alchemy to Chemistry

  Alchemy made important contributions to metalworking, production of gunpowder, ceramics, glass, ink, dyes, paints, cosmetics, extracts and liquor preparations, medicine, distillation, extraction, etc
• Atomism


  Our physical universe is composed of indivisible components called atoms
• People who practiced alchemy were called Alchemists
• John Dalton converted atomic philosophy into atomic chemistry and provided the experimental foundation of atomic chemistry
• Alchemy


  • Based on the belief that there are four basic elements in nature: air, fire, water, and earth
  • Quest that has captured the imaginations of people for thousands of years
• Alchemists learned the properties of numerous chemical substances and improved our understanding of basic chemistry
• Alchemy aimed at the great human goods: Wealth, Longevity, and immortality
• Dalton's Atomic Theory


  • All matter consists of extremely small particles called atoms
  • Atoms are indestructible and resist change
  • Elements are characterized by the mass of their atoms
  • When atoms are involved in chemical reactions, they combine in small whole-number ratios to form molecules
• Alchemists believed that consuming transmuted gold was the secret to immortality, known as the elixir of life or the philosopher's stone
• J.J Thomson discovered the Electron and is known for the Cathode Ray Tube Experiment