REMEMBER: Exam #1 Friday, February 25 in Individual Classrooms

1. REMEMBER: Exam #1Friday, February 25in Individual Classrooms

2. Topic 5Early Ideas About Matter Dr. George Lapennas Department of Biology

3. Outline 1. Contrast study of motion with study of matter 2. What ideas make up modern view of matter? 3. What types of matter were ancient people aware of? 4. What were Greek philosophers’ ideas about matter? 5. What were some significant later chapters in the study of matter?

4. 1. How do study of motion and study of matter compare? • Newton’s theory of universal gravitation • A major triumph of early science • Gravity: a universal property of all matter • Strength of attraction a simple function of mass, regardless of material

5. 1. How do study of motion and study of matter compare? • Newton’s theory of universal gravitation • A major triumph of early science • Gravity: a universal property of all matter • Strength of attraction a simple function of mass, regardless of material • What about properties that distinguish themany different types of matter?

6. 2. What ideas make up our modern view of matter?

7. One Classification of Matter: Phases • Bottle A: GAS • Bottle B: LIQUID • Bottle C: SOLID

8. Another Classification Scheme for Matter

9. “The Basics”:How Do We Understand Matter Today? • Everything is made of atoms. • Atoms are made of protons (p+), neutrons (n), and electrons (e-). • Atoms come in ~ 100 different kinds = elements • Each element has a characteristic number of protons and electrons. • Atoms share electrons to form molecules. • Chemical reactionsrearrange atoms in molecules.

10. Atoms are Made of Protons, Neutrons, and Electrons. An atom is really, really, really small! Trillions in speck of dust!

11. Atoms are not all the same. - Each element has a different and unique number of protons (“atomic #”) • # of protons = # of electrons - # of neutrons varies between different isotopes of an element

12. Atoms have their electrons arranged in orbit-like “shells”

13. Atoms share electrons, filling outer shells and forming bonds and molecules

14. Atoms combine to form molecules • Molecule = two or more atoms bonded together • Most molecules contain atoms of more than one element (“compounds”), but not necessary (can be 2 or more atoms of the same element) • Chemical formula tells how many atoms of each element are in the molecule: • Water is H2O • Ammonia is NH3 • Oxygen is O2 • Glucose is C6H12O6

15. What determines the “chemical” (combining/reacting) properties of each element? • # of protons = # of electrons • Atoms tend to share electrons so as to fill their outer electron shells • Greater number of empty spaces in outer electron shell  more bonds can be made • “Families” of elements have similar outer electron shells and similar bonding properties

16. Chemical reactionsrearrange bonding of atoms • Total number of atoms does not change • Products have same atoms as Reactants (conservation of atoms) • Only bonding arrangement of atoms changes. • Methane + oxygen  carbon dioxide + water CH4 + 2 O2 CO2 + 2 H2O 1 Carbon, 4 Hydrogen, 4 Oxygen, before and after

17. 3. What Types of Matter Were Ancient People Aware of?

18. Stone (hard, brittle) • Limestone • Marble • Sandstone • Shale • Granite • Soapstone

19. Metal (shiny, malleable) • Copper • Silver • Gold • Tin • Iron • Lead • Zinc

20. Metal (shiny, malleable) • Copper • Silver • Gold • Tin • Iron • Lead • Zinc

21. Metal (shiny, malleable) • Copper • Silver • Gold • Tin • Iron • Lead • Zinc

22. Metal (shiny, malleable) • Copper • Silver • Gold • Tin • Iron • Lead • Zinc

23. Where do metals come from? • A few metals occur naturally in metallic form - Copper, silver and gold deposits found in ancient times Found copper nuggets

24. Where do metals come from? • Most metals occur in ores • Ores are more like earths (dull, brittle) than like metals Iron ore Lead ore

25. Winning metals from their ores • Ores must be processed to yield pure metals • Only a small percentage of metal yielded copper ore; modern man’s inept attempt at smelting

26. Alloys • Combination of metals • Better properties • Lower melting point • Stronger, less brittle • Example: Bronze • Alloy of copper and tin

27. Metal working in cultural eras • Stone age • Stone tool manufacture, no use of metals • Pre-Copper Age: found gold/silver/copper only • Copper Age (4500 BC): first metal smelted • Bronze Age (3500 BC): strong copper/tin alloy • can be sharpened, easily worked (shaped) • copper and tin deposits only in certain places • Iron Age (1500 BC on): • Can be sharpened; hard and tough • Difficult to work • Iron ore is found all over the Earth • Extremely hard to win from ore (requires very hot furnace, special techniques)

28. Metal working in cultural eras

29. Earths (not shiny; brittle • Clay • Mud • Sand • Silt • Loam • Ash

30. Pottery • Fired clay • from 6500 BC? • Certain clays used • at certain temperature • for certain times • Patterned, pigmented

31. Glass • Melted sand • Certain sands used • High temperatures • Blown, molded • Earths, metals added  color, strength Ancient Roman glass jug

32. Glass

33. Woods • Oak • Maple • Cedar • Mahogany • Ebony • Yew

34. Fibers • Grass • Cotton • Flax • Straw • Bulrushes • Hair

35. Papyrus

36. Ivory, bone and horn

37. A bone tool

38. Other crafts practiced since early times • Pigments • Dyes • Perfumes • Fermenting drinks • Tanning • Cooking

39. Summary: What types of matter were ancient people aware of? • Ancient peoples distinguished many different materials. • Craftsmen and artisans had developed many materials technologies. • These technologies were applied knowingly to specific materials for specific purposes.

40. 4. What were ancient Greek philosophers’ ideas about matter? • One fundamental substance? (If so, what?) • More than one (e.g., four)? • Fill space (no “void”)? • Small particles moving in void (“atoms”)?

41. Nature of matter: One basic substance 1. Thales (640–546 BC) • Basic element is water. • In greatest quantities • Found as solid, liquid, and gas

42. Nature of matter: One basic substance 2. Anaximander All matter from one “boundless something” that contained all qualities (wet/dry; hot/cold)

43. Nature of matter: One basic substance • 3. Anaximenes • (570 BC) • - Airis the one basic substance • - All space above Earth is air. • Compress air to form denser • water and earth

44. Nature of matter: One basic substance • 4. Heraclitus • (540-475 BC) • Change is a • fundamental characteristic • Basic element • must be changeable • Fire is that element.

45. Empedocles / Aristotle(490 – 430 BC) (384-322 BC) Four elements: Fire Air Water Earth

46. Four Elements Theory (Empedocles/Aristotle) Each element has certain amounts of the qualities Wet/Dry and Hot/Cold

47. Each different kind of matter is a combination of two or more elements in particular proportions, for example … Wood reveals its composition when it burns: • fire issues from it • water oozes from it/hisses • air (smoke) is produced from it • earth (ashes) remain behind

48. Transmutations • Alter proportions of qualities = change one element into another. Examples: Add more heat to waterair when it evaporates Idea carries over into alchemy: Transmute a cheap metal into gold by adjusting proportions of the four elements

49. Different approach: Ancient “atomist” philosophers Leucippus and Democritus (~400 BC) One fundamental material – same in all matter Small, indivisible particles (“atoms”) Many different sizes and shapes give different properties to matter Atoms move in empty space (“void”) OR Clump together

50. Atoms, then and now…