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

-- ? --

Structure & nature of matter changes when:

• Wood burned

• Foods cooked

• Clays fired to make bricks and pottery

• Metals smelted

What types of Matter were ancient people aware of?

Gold

Silver

Copper

Iron

Mercury

Lead

Tin

“Seven Metals of the

Ancients”

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

Iron Furnace

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

Ivory, bone, and horn

Fibers

• Grass

• Cotton

• Flax

• Straw

• Bulrushes

• Hair

Papyrus

Other crafts practiced since early times

• Pigments

• Dyes

• Perfumes

• Fermenting drinks

• Tanning

• Cooking

• Ancient peoples distinguished many different materials

• Engineers and artisans had developed many material technologies

• These technologies were applied to specific materials for specific purposes

Early Chemical Technology

Unification

• Huge diversity

• Fundamental principles exist?

• Which properties important?

• Categorization

What do we know now?

One Classification of Matter: Phases

• Bottle A:

GAS

• Bottle B:

LIQUID

• Bottle C:

SOLID

Another Classification Scheme for Matter

MATTER

Pure Substances Mixtures

Homogeneous Mixtures

Heterogeneous Mixtures

CompoundsElements

Everything is Made of Atoms

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

Each Element Has a Different Number of Protons

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) - Air is the one basic substance - All space above Earth is air.-Compress air to form denserwater and earth

Hericlitus (540 – 475 B.C.)

• If change characterized the Earth . . .

• Basic element must be changeable

• That element must be fire

Empedocles (490 – 430 BC)

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

Each different kind of matter is a combination of two or more elements in particular proportions, for example …

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

Matter

• marble

Form

• shape

Matter

• 4 elements

Form

• specific combination of elements

Statue

Individual Elements

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

Transmutations• Alter proportions of elements =

change one type or matter into another.

Idea carries over into alchemy:

Transmute a cheap metal into gold by

adjusting proportions of the four elements

Greek “Atoms”

• Question of divisibility of matter

• Break a stone and it is still a stone

• Leucippus (c. 450 B.C.) eventually no further division

Democritus (470 – 380 B.C.)

• Atomos – indivisible – move in empty space (void)

• One fundamental material

• Many different sizes and shapes gave different properties to elements

• Aristotle wins – atomist idea died out

Alexander the Great (356 – 323 B.C.)

Early Laboratory Chemistry = Alchemy

Sorcerer's Apprentice

Beginnings of Alchemy

• Emphasis on degrees of purity/nobility

~ Gold most pure and noble

~ “Maturation” of minerals in ground

• Incorporated Aristotle’s four elements

• Greek Philosophy – Egyptian craftsman

Transmutation as goal of Alchemy(wealth – longevity – immortality)

• Chemical

~ transform base metals silver / gold

• Physiological

~ Sickness Health

~ Old-age Youth

~ Earthly Supernatural Existence

The Alchemical Tradition

• Origins: ~ Greece (Hellenistic) ~ China ~ India

• Further developed by Arabs • Inherited by medieval Europeans • Part practical chemistry, part spiritual

quest

Hellenistic Alchemy

• Transmutation of base metals to gold

• Spiritual Purification

Hermes Trigmegistus

Eastern/Chinese Alchemy

• Independent of (and prior to?) Western alchemy

• Gold is eternal and healing, led to medical alchemy:

• Search for the “Elixir of Life,”

• Soluble “potable gold” (400 BC) a potion for eternal life

Indian Alchemy

• Mineral remedies for specific diseases

• Promote long life (not immortality)

Arab/Islamic Alchemy

• Arabic alchemists – add mercury and sulfur

• Used “al-iksurs” (colored “seed” catalysts) in transmutation attempts.

• Arabic alchemists – philosopher’s stone to stimulate transmutation

• Combustible principle = phlogiston theory

Importance of Medicine

• Problems: crowded, unsanitary, infested homes; contaminated food/water; low life expectancy.

• Physicians in medieval Europe

- Most followed ideas of Hippocrates (460-370 BC) and Galen (129-200 AD).

- Disease = imbalance in 4 body humours.

• Inorganic substances and alcohol could fight infection, but not favored by Galenists.

Ibn-Sina/Avicenna ( 980-1037)

• Greatest physician of his time

• Believed in Four Elements but not transmutation.

• Contributions:~ dosage effect of drugs~ Had idea that chemicals maintain identity even when combined

Paracelsus (1493 – 1541)• At odds with the dominant

medical establishment

• Disease spread between persons (external cause?) contrary to Galen’s ideas

• Founded Iatrochemistry (Alchemy for medicinal purposes)

• Iatrochemist’s legacy – legitimacy of chemistry

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.”

Gold

Elixirs

Immortality

Superior Medicines

Accomplishments of Alchemy

• Laboratory apparatus

• Practical chemical knowledge, techniques, and reactions despite incorrect theories

• Quantitative methods

• New substances