REMEMBER: Exam #1 Friday, February 25 in Individual Classrooms Topic 5 Early Ideas About Matter Dr. George Lapennas Department of Biology 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? 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 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 the many different types of matter? 2. What ideas make up our modern view of matter? One Classification of Matter: Phases • Bottle A: GAS • Bottle B: LIQUID • Bottle C: SOLID Another Classification Scheme for Matter MATTER Pure Substances Elements Compounds Mixtures Homogeneous Mixtures Heterogeneous Mixtures “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 reactions rearrange atoms in molecules. Atoms are Made of Protons, Neutrons, and Electrons. An atom is really, really, really small! Trillions in speck of dust! 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 Atoms have their electrons arranged in orbit-like “shells” Atoms share electrons, filling outer shells and forming bonds and molecules 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 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 Chemical reactions rearrange 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 3. What Types of Matter Were Ancient People Aware of? Stone (hard, brittle) • Limestone • Marble • Sandstone • Shale • Granite • Soapstone Metal (shiny, malleable) • • • • • • • Copper Silver Gold Tin Iron Lead Zinc Metal (shiny, malleable) • • • • • • • Copper Silver Gold Tin Iron Lead Zinc Metal (shiny, malleable) • • • • • • • Copper Silver Gold Tin Iron Lead Zinc Metal (shiny, malleable) • • • • • • • Copper Silver Gold Tin Iron Lead Zinc 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 Where do metals come from? • Most metals occur in ores – Ores are more like earths (dull, brittle) than like metals Iron ore Lead ore 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 Alloys • Combination of metals • Better properties – Lower melting point – Stronger, less brittle • Example: Bronze – Alloy of copper and tin 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) Metal working in cultural eras 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 Glass Woods • • • • • • Oak Maple Cedar Mahogany Ebony Yew Fibers • • • • • • Grass Cotton Flax Straw Bulrushes Hair Papyrus Ivory, bone and horn A bone tool Other crafts practiced since early times • • • • • • Pigments Dyes Perfumes Fermenting drinks Tanning Cooking 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. 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”)? Nature of matter: One basic substance 1. Thales (640–546 BC) • Basic element is water. • In greatest quantities • Found as solid, liquid, and gas Nature of matter: One basic substance 2. Anaximander All matter from one “boundless something” that contained all qualities (wet/dry; hot/cold) Nature of matter: One basic substance 3. Anaximenes (570 BC) - Air is the one basic substance - All space above Earth is air. -Compress air to form denser water and earth 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. Empedocles / Aristotle (490 – 430 BC) (384-322 BC) Four elements: Fire Air Water Earth Four Elements Theory (Empedocles/Aristotle) Each element has certain amounts of the qualities Wet/Dry and Hot/Cold 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 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 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 Atoms, then and now… What were the most significant later chapters in the study of matter? • Alchemy • Scientific Revolution • Chemical Revolution Alchemy (“the hidden art”) Alchemy • Greek-influenced alchemy • Eastern/Chinese Alchemy • Arab/Islamic alchemy • Arab traditions passed to medieval Europeans • Paracelsus • Iatrochemists Greek-influenced Alchemy (300 BC – 650 AD) Two branches: • Esoteric: religious/astrological, attempt to understand god/gods and find salvation. • Exoteric: worldly/magical, wealth-focused - Related to Four Elements/Qualities: search for the “Philosopher’s Stone” to transmute base metals into gold - Sulfur and mercury were magical Eastern/Chinese Alchemy • Independent of (and prior to?) Western alchemy • Chinese believed there were five elements: Fire, Water, Three Solids (Earth, Wood, Metal) • Search for the “elixir of life,” a potion for eternal life • Gold is eternal and healing, lead to medical alchemy: soluble “potable gold” is the elixir of life (400 BC) Arab/Islamic Alchemy (approx. 700-1200 AD) • Used “al-iksurs” (colored “seed” catalysts) in transmutation attempts. • Stressed techniques to isolate/identify/purify • Noted alchemists/scientists: al-Kindi, al-Razi, Jabir (Geber), ibn-Sina (Avicenna) Ibn-Sina, Avicenna (980-1037 AD) Islamic physician, poet, scientist, philosopher Avicenna • Greatest physician of his time (980-1037 AD) • Believed in four elements, but not transmutation • Contributions: - studied dosages and effects of drugs - had idea that chemicals maintain their identities even when combined Franciscan medicine • Roger Bacon (1267) - medical alchemist - distillates used as medicine to fight body corruption. • John of Rupescissa (1320) - alcohol contains “quintessence” for elixir of life - Chinese-influenced use of “potable gold” - followers distilled to get purer chemicals and thus found new substances. Paracelsus (Theophrastus von Hohenheim) (1493-1541) Swiss physician, mystic, alchemist Paracelsus (Theophrastus von Hohenheim) • Alchemy = study of the cosmos - he chose medicines on basis of astrological connections • Founded science of iatrochemistry - use of inorganic medicines rather than herbal ones Paracelsus’ idea of elements and principles • Three Elements (Fire, Air, Water) and Three Principles of Earth (sulfur, mercury, and salt) • Wood burning: “That which burns is sulfur, that which vaporizes is mercury, and that which turns to ashes is salt.” Lasting Contributions of Alchemy • • • • Laboratory equipment Chemical techniques New chemical reactions New substances The Scientific Revolution - Copernicus …… Newton - a new way to study the natural world - Better explanations for earthly and heavenly motion The Chemical Revolution: Applying the scientific method to study different kinds of matter - Black …… Lavoisier - Key chemists of the 1700’s studied different kinds of “airs” (Black, Cavendish, Priestly, Lavoisier) - Redefinition of “element” - Conservation of atoms REMEMBER: Exam #1 Friday, February 25 in Individual Classrooms