remember: exam #1 friday, february 25 in individual classrooms

REMEMBER:

Exam #1

Friday, February 25

in Individual Classrooms

Topic 5Early 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 Mixtures

Homogeneous Mixtures

Heterogeneous Mixtures

CompoundsElements

“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 inspeck 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

• 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

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 denserwater and earth

Nature of matter: One basic substance

4. Heraclitus(540-475 BC)• Change is afundamental 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)

Eachelement hascertainamounts ofthe qualities

Wet/Dry

and

Hot/Cold

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 …

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

• 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.

• Roger Bacon (1267) - medical alchemist - distillates used as

medicine to fight body corruption.

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