680 likes | 813 Views
Exam # 1 Friday, 24 February Individual Classrooms. Early Ideas About Matter. Motion - Matter. Gravity universal property of all matter strength of attraction is function of mass, regardless of material Fundamental property to distinguish different types of matter -- ? --.
E N D
Motion - Matter • Gravity • universal property of all matter • strength of attraction is function of mass, regardless of material • Fundamental property to distinguish different types of matter -- ? --
Structure & nature of matter changes when: • Wood burned • Foods cooked • Clays fired to make bricks and pottery • Metals smelted
Gold Silver Copper “Seven Metals of the Ancients” Iron Mercury Lead Tin
Metal (shiny, malleable) • Gold • Silver • Copper • Iron • Mercury • Lead • Tin
Metal (shiny, malleable) • Gold • Silver • Copper • Iron • Mercury • Lead • Tin
Metal (shiny, malleable) • Gold • Silver • Copper • Iron • Mercury • Lead • Tin
Metal (shiny, malleable) • Gold • Silver • Copper • Iron • Mercury • Lead • Tin
Where do metals come from? • A few metals occur naturally in metallic form - Gold and silver deposits were found in ancient times
Where do metals come from? • Most metals occur in ores • Ores are more like earths (dull, brittle) than like metals Iron ore Lead ore
Smelting metals from their ores • Ores must be processed to yield pure metals • Only a small percentage of metal yielded • copper ore and modern man’s inept attempt at smelting
Alloys • Combination of metals • Better properties • Lower melting point • Stronger, less brittle • Example: Bronze • Alloy of copper and tin
Stone Age ~ stone tool manufacture, no use of metals
Copper Age (4500 BC) ~ first metal smelted
Bronze Age (3500 BC) ~ tin/copper alloy ~ copper & tin deposits only in certain areas ~ strong easily worked
Iron Age (1500 BC on) ~ found all over ~ can be sharpened; hard and tough ~ difficult to work ~ required hot furnace & special techniques
Earths (not shiny, brittle • Clay • Mud • Sand • Silt • Loam • Ash
Pottery • Fired clay • from 6500 BC? • Certain clays used • at certain temperature • for certain times • Patterned, pigmented
Glass • Melted sand • Certain sands used • High temperatures • Blown, molded • Earths, metals added color, strength Ancient Roman glass jug
Stone (hard, brittle) • Limestone • Marble • Sandstone • Shale • Granite • Soapstone
Woods • Oak • Maple • Cedar • Mahogany • Ebony • Yew
Fibers • Grass • Cotton • Flax • Straw • Bulrushes • Hair
Other crafts practiced since early times • Pigments • Dyes • Perfumes • Fermenting drinks • Tanning • Cooking
Early Chemical Technology • Ancient peoples distinguished many different materials • Engineers and artisans had developed many material technologies • These technologies were applied to specific materials for specific purposes
Unification • Huge diversity • Fundamental principles exist? • Which properties important? • Categorization
One Classification of Matter: Phases • Bottle A: GAS • Bottle B: LIQUID • Bottle C: SOLID
Atoms Combine to Form Molecules • Most materials are made of more than one type of atom • Chemical formula gives atomic makeup • Water is H2O • Ammonia is NH3 • Glucose is C6H12O6
What Determines Chemical Properties of Each Element? • Usually, # of protons = # of electrons • Electrons tend to fill shells surrounding nucleus • Outer shell stability
Chemical Reactions Rearrange Atoms • Number of atoms does not change • Reactants have same atoms as products • Only arrangement of atoms change • Different molecules after reaction • Methane + oxygen gas carbon dioxide + water • CH4 + 2O2 CO2 + 2H2O • One carbon, two oxygen, four hydrogen (before & after)
What is the true nature of a substance? • Does one basic material exist?
Thales(640 – 546 B.C.) • Basic element is water • In greatest quantities • Found as solid, liquid, and gas
Nature of matter: One basic substance Anaximander All matter from one “boundless something” that contained all qualities (wet/dry; hot/cold)
Nature of matter: One basic substance • Anaximenes • (570 BC) • - Airis the one basic substance • - All space above Earth is air. • Compress air to form denser • water and earth
Hericlitus (540 – 475 B.C.) • If change characterized the Earth . . . • Basic element must be changeable • That element must be fire
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
Four Elements / Four Qualities of the Ancient Greeks • Elements had four qualities: Dry vs. Moist & Hot vs. Cold • Qualities combined in various pairs to form the different elemental components of the Earth
Individual Elements Statue Matter • 4 elements Matter • marble Form • specific combination of elements Form • shape
Individual Elements Form •qualities Ultimate Matter •prima materia
One element to another element • Change qualities = change 1 element into another element Elements themselves were interchangeable: Water air when it evaporates (wet-cold wet-hot) Air water when it rains (wet-hot wet-cold)
Four elements and alchemy • Aristotle’s four element theory was to exert a considerable influence on the practice of alchemy and the idea of transmutation