• Like
Ch08
Upcoming SlideShare
Loading in...5
×
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
490
On Slideshare
0
From Embeds
0
Number of Embeds
1

Actions

Shares
Downloads
9
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. The Atom Chapter 8 Great Idea: All of the matter around us is made of atoms, the chemical building blocks of our world
  • 2. Chapter Outline
    • The Smallest Pieces
    • The Structure of the Atom
    • When Matter Meets Light
    • The Periodic Table of the Elements
  • 3. The Smallest Pieces
  • 4. The Smallest Pieces
    • Democritus
      • Cut matter to reach smallest piece
      • Called “the atom” or “uncuttable”
      • All material formed from atoms
  • 5. Dividing a Bar of Gold
  • 6. Elements
    • John Dalton
      • Father of modern atomic theory
      • Cannot break down elements
      • Elements composed of atoms
        • Example: Water molecule is 1 oxygen atom and 2 hydrogen atoms
  • 7. Envisioning Atoms
  • 8. Are Atoms Real?
    • Evidence for the reality of atoms
      • Behavior of a gas
      • Chemical combinations
      • Radioactivity
      • Brownian motion
      • X-ray crystallography
      • Atomic-scale microscopy
  • 9. The Behavior of a Gas
    • Bernoulli
      • Atoms have mass and velocity and thus kinetic energy
    • Decreasing volume increases pressure
    • Increasing temperature increases pressure
  • 10. The Behavior of Gases
  • 11. Chemical Combinations
    • Dalton applied law of definite proportions
      • Elements combine in a specific ratio of weights
        • Ex: Water is 8 parts oxygen to 1 part hydrogen
  • 12. Chemical Combinations (cont.)
    • Ratio of weights is a small whole number
      • Ex: 12 lbs carbon can combine with either 16 lbs or 32 lbs of oxygen
    • Implication: some units of elements are fundamentally indivisible
  • 13. Radioactivity
    • Radioactivity
      • Discovered in 1896
    • Phosphors flash when hit by radiation
    • 1903 demonstration of the twinkling caused by this effect
  • 14. Brownian Motion
    • Brownian motion: erratic, jiggling motion
      • Pollen grains suspended in water
    • Einstein: motion is random collisions of atoms
      • Predicted particle movement
    • Perrin tested and confirmed Einstein’s predictions
  • 15. X-ray Crystallography
    • Developed in 1912
    • Demonstrates arrangement of atoms in crystals
  • 16. Discovering Chemical Elements
    • Electrolysis
    • Mendeleev
    • Current periodic table
      • 112 elements
        • 92 found in nature
  • 17.
      • Helium, carbon, aluminum, copper, gold
    Everyday Elements
  • 18. The Structure of the Atom
  • 19. The Structure of the Atom
    • Joseph Thomson identified electron
      • Negatively charged
      • Smaller and lighter than smallest atom
    • Atoms are NOT fundamental building blocks, but are made up of smaller more fundamental particles
  • 20. The Atomic Nucleus
    • Ernest Rutherford determined atomic structure
    • Concluded
      • Atom has nucleus at center surrounded by electrons
    • Later discoveries found nucleus is composed of protons and neutrons
  • 21. Rutherford’s Experiment
  • 22. Important Terms Related to Atoms
  • 23. Why the Rutherford Atom Couldn’t Work
    • Why?
      • Object in circular orbit is accelerating
      • Accelerated electrical charge emits electromagnetic radiation
      • Electrons giving off energy while orbiting
        • Result: electrons spin toward nucleus and eventually atom ceases to exist
    • Rutherford atom exists <1min
  • 24. The Nuclear Regulatory Commission
    • Logo: highly stylized atomic model
  • 25. When Matter Meets Light
  • 26. Niels Bohr
  • 27. The Bohr Atom
    • First working model of atom
    • Energy levels for electrons
      • Specific distances from nucleus
      • Electrons exist with no radiation
      • Electrons cannot exist between allowed distances (energy levels)
  • 28. Bohr Atom
  • 29. Electron Energy Levels
  • 30. Atomic Model
  • 31. Photons: Particles of Light
    • Photon absorbed
      • Used to move electron to a higher energy state
    • Photon emitted as electron moves to lower energy state
  • 32. Photons: Particles of Light
  • 33. Photons - cont.
    • Quantum leap or jump -electron disappears from original location and reappears in final location- never at positions in between
  • 34. Energy in Bohr Atom
    • Energy required to leave ground state
      • Absorb photon
      • Heat
        • Increases collisions
  • 35. Spectroscopy
    • Atoms emit and absorb different photons
    • Depends on differences between energy levels
    • Each atom has distinct set of photons
    • Spectrum: all photons emitted by an atom
      • Used for identification
  • 36. Na, K, and Li – Give Distinctive Colors to a Flame
  • 37. Spectroscopy – cont.
    • Glass prism
  • 38. Spectroscopy – cont.
    • Line spectra for H, Na, and Ne
  • 39. The Periodic Table of the Elements
  • 40. The Science of Life
    • Spectra of life’s chemical reactions
      • Used to determine how enzymes work
      • Used to identify pollutants emitted from automobile exhaust pipes
  • 41. Science in the Making
    • Helium
      • Discovery
      • Properties
  • 42. Technology
    • Lasers
      • Produce a beam of light
  • 43. Action of a Laser
  • 44. Lasers Have Many Uses
  • 45. Periodic Table of the Elements
    • Systematizes elements
    • Columns contain similar elements
      • Alkali metals: soft, silvery metals
      • Noble gases: colorless, odorless, and inert
  • 46. Periodic Table of the Elements
  • 47. Why the Periodic Table Works: Electron Shells
    • Patterns mirror arrangement of electrons in shells
    • Pauli exclusion principle
    • First shell 2 electrons, second shell 8, etc.
  • 48. Electron Representation