Materials of Civilization EVSC 201
What were the 8 metals of antiquity?
gold, silver, copper, iron, tin, zinc, lead, mercury
Why were metals like gold, silver, copper among the first to be used by man?
they are more likely to be found in native state because they are chemically inert.
: What technology most likely had to be developed first, prior to the widespread use of metals?
Answer: controlled fire, furnaces for smelting (perhaps through the development of pottery firing)
Question: Why was copper widely used prior to iron, which is both stronger and much more common in the earth’s crust?
Answer: Copper has a much lower smelting temperature than iron.
Question: Why can it be truthfully stated that the first iron implements used by man were fabricated out of iron which came from heaven?
Answer: The first iron used came from meteorites
Question: The earliest widespread use of iron took place within the bounds of which present day nation?
Turkey
Question: Define amalgamation and state a common use in its early history.
Answer: Amalgamation is the combining of mercury with other metals. One use was to recover gold from objects such as clothes.
Task: Name and list the symbols for the eight metals of antiquity _____________________________
Answer: gold (Au), silver (Ag), copper (Cu), tin (Sn), iron (Fe), lead (Pb), zinc (Zn), mercury (Hg)
Who obtained iron from ore during the early iron age? What was this iron like
Hittites
spongy
How were the Hittites able to transform the spongy iron they obtained from ore into a compact metal?
Hammering it while it was glowing hot
Task: List three stages (and examples) man appears to follow during the development of new technology…
Answer: a. Use of materials as they are found in nature, such as adequately shaped stone; naturally occurring fire, e.g. from lightening; native copper; meteoric iron.
b Modification or refinement of a naturally occurring tool (shaping of stone tools; tending of fire; manufacture of clay or mud vessels)
c Manufacture of new materials or radical departure from naturally occurring substances (kindling and controlling fire with furnaces; firing of pottery; smelting of metals from ore)
Question: What marked the transition from paleolithic to mesolithic eras?
Answer: The refinement of stone tools, from suitably shaped natural stones to finely shaped and polished axes and knives.
Question: What materials technology has been an important tool for archeologists trying to date their findings because of its distinct stages of development and cultural designs?
Answer: Pottery
Question: Technology proceeds at an ever accelerating pace. What technological leap led to a tremendous surge in technology and culture during the neolithic age?
Answer: Agriculture
Question: Although human-like beings have been using fire for probably at least a million years, the purposeful control of fire temperatures, mainly to achieve greater heat was developed only about 7,000 to 10,000 years ago. What were the major reasons for, and/or consequences of, developing that skill?
Answer: The need to fire pottery to make it waterproof. As a result of better control of fire, metal extraction became possible a few thousand years later.
Put the stages of human development discussed in this class in chronological order.
Paleolithic Mesolithic Neolithic Copper Bronze Iron
Question: Obsidian is a glassy material used by ancient people for what purpose?
cutting tools
Task: Name at least 3 out of 4 changes in lifestyle of our ancestors that took place with the on-set of agriculture in the Neolithic period.
Answer: permanent settlements, stabilized food supply, rapid population increase, leisure time permitting arts and experimentation
Question: What was the most important reason for glazing pottery in ancient times?
Answer: To make it impermeable to liquids (water)
Question: Why is it impossible to assign specific dates to the early and middle stone ages?
Answer: The peoples living within a certain region, and the region itself, determine when the early stone age was over and the middle stone age began. Different regions evolved at different rates. For some groups of people and some regions the middle stone age is not over even now.
Question: The notes to this lecture include a number of wood cut reproductions from the book ‘De Re Metallica’. a) Who translated the book into English? b) What do these wood cuts show?
Answers: a) The past U.S. President Herbert Hoover and his wife Lou Henry
b) Various metallurgical and mining processes of the fifteenth and sixteenth century.
Question: Who/what culture developed and refined the Indian invention of Wootz steel leading to Damascene steel/Toledo steel through a process of steel-making similar to that used in making Japanese swords?
Answer: The early Muslims, in Damascus, Syria, as well as in Toledo while the Moors ruled Spain
Question: In which way, and more or less when, was the classical knowledge, that had been lost during the Dark Ages in Europe, recovered?
Answer: When the Muslims conquered the Greek-language East Roman Empire (Byzantium, capital city Con-stantinople, now Istanbul in Turkey) about 700 AD, they took over and carefully preserved the bulk of the Greek books and knowledge they found there, while in the Latin-speaking West Roman Empire, book burning had already destroyed almost all of the ancient “heathen” knowledge by about 500 AD. Through the Crusades, Christians and Muslims came into close contact beginning about 1000 AD, and the West became re-acquainted with the classical Greek literature.
Question: In the centuries following the fall of Rome, i.e. in the ‘Dark Ages’, on account of book-burning and misguided religious fervor, the heritage of the Roman-Greek culture was lost in Western Europe. How was it preserved and how became the West reacquainted with it?
Answer: Greek continued to be the language of the East Roman empire. On conquering it, the Muslims preserved the antique heritage. The West became reacquainted with it through the Crusades that brought intimate ( albeit mostly initially hostile) contacts between Christians and Muslims.
Question: Before the invention of the steam engine, most labor was performed by humans, animals, wind or water power. What particular work in connection with mining and metallurgy was frequently done by horses?
Answer: Hauling of ore out of mines and working bellows to fan fires (e.g. for smithing) or providing fresh air for miners underground.
Question: The Muslim Moors in Spain (711AD to 1479AD) discovered a method of making copper with only modest heating. How was this done?
Answer: They “roasted” (i.e. heated moderately in the open air) copper sulfide ores, thereby oxidizing them into CuSO4 (blue vitriol). Then they dissolved the CuSO4 in water which yields the blue solution demonstrated in class, and ran over scrap iron, whereby the copper plates out on the iron and can be scraped off.
Question: What is the origin of the saying “this is Greek to me” and what does that have to do with our course.
Answer: Book-burning in the Dark Ages led to the loss of the knowledge of Greek in the Christian West. An-cient documents written in Greek could no longer be read there. “This is Greek to me” thus means that I cannot read (or understand) this. Through the crusades, the West re-established contacts with the Mu-slims who had carefully preserved the ancient Greek documents, and the ability to read them. Eventually, the influx of much ancient knowledge rejuvenated Western arts and sciences, in the “renaissance”.
Task: The industrial revolution was triggered by the invention of machines, beginning with the steam engine, which could substitute for human labor. Before then, human labor was assisted by (a) water power and (b) horse power. Give at least one example each for (a) and (b) and briefly explain
Answer: (a) The water wheel: Water flowing through are reasonably sized height differential turns a wheel. Various tools may be attached to the axel that perform work, e.g. crushing of ores in a stamping mill. As (a) but using a horse, e.g. to operate bellow for a smith.
In the time of the Roman empire, iron-making was already wide-spread in Europe
True
In the time of the Roman empire, iron-making was already wide-spread in Europe
True
In Louis XIV’s palace of Versailles in France, there are still operative cast iron water pipes
True
Task: Name at least two early industrial uses of water power
Answer: Stamping works (for crushing ores or pig iron). Auxiliary aid in wire drawing. Operating bellows for fanning fire, e.g. in smithing.
Task: In Elizabethan England there was a severe “energy crisis”. What was it, how was it caused and how was it resolved?
Answer: Rapidly rising iron production depleted the forests of mature trees because the blast furnaces required char coal gained from wood. Consequently the price of fuel wood for heating and cooking rose steeply. The discovery that coal could be converted to coke, much like wood to charcoal, and that coke could be used in blast furnaces resolved the crisis.
Question: Name at least three important methods for metal forming
Answer: Casting (of molten metal into forms), forging/swaging/hammering, cutting methods (including turning in a lathe, grinding, drilling, milling), drawing (of sheet, e.g. as in making car bodies, air plane bodies and much, much else).
Task: Indicate the major steps involved in winning a metal from its ore, beginning with the ore being delivered to the processing facility and ending with the finished metal.
Answer: Excavating or mining the ore. Hauling to processing plant. Sorting out obvious “tailings” and discard-ing them. Milling extremely finely. Separate the remaining “tailings” via floatation. Processing so as to “reduce” the ore (mainly through heating but sometimes also making use of electrolysis.
Task: The rapid evolution of steel making in England beginning in the Renaissance gave rise to a severe “energy crisis”. Please explain.
Answer: Steel-making requires a great deal of clean fuel which until a few hundred years ago was solely char-coal, obtained from wood via moderate prolonged heating under exclusion of air. This drives out the sap and impurities in the form of tar. In order to satisfy an ever increasing demand for iron and steel, trees were felled at a much faster rate than they could re-grow. As a result wood, not only for feeding blast furnaces but also for heating and cooking, became scarce and correspondingly expensive. The crisis was resolved through the discovery that coal can be purified in much the same manner as wood, namely through prolonged heating under exclusion of air, thereby producing coke which can be used in blast furnaces.
Question: Chemically, what is the distinguishing feature of metals, and what is “metallic bonding”?
Answer: In the neutral state single metal atoms have one, two or three loosely bound electrons in their outermost shells. These are called “conduction electrons” and in the metallic state are shared among the atoms without fixed positions. Thereby the atoms are held together, i.e. in the “metallic bond”.
Question: What are metal “ores”?
Answer: Ores are chemical compounds (often intermixed with “tailings”) which contain metals that are chemically bound such as to lend one, two or three of their outermost electron(s) to non-metals. very often oxygen.
Question: What is meant by “oxidation”, specifically of a metal?
Answer: In the chemist’s language, “oxidation” means a chemical reaction in which one or more electrons per atom are lent to another element. Thus in ores metals are present in “oxidized” form, even if they are bonded with sulfur, phosphorous etc.
Question: The bulk of all our metals are “reduced” from their ores, what does this mean and what treatments are typically involved?
Answer: Winning the metal from the ore means “reducing” them, i.e. reversing “oxidation” through giving them back their electrons. Typically this involves high heat, such as in blast furnaces, and it requires “fluxes”, i.e. chemical elements or compounds which bind the non-metals from the ores and thereby return the electrons back to the metal atoms.
Question: Why (with the exception of noble metals) are metals overwhelmingly found in the form of ores?
Answer: Oxidization in the form of “weathering” and corrosion of base metals takes place spontaneously and over the vast geological time span has bound metals into ores
Question: In terms of electrons how are metals extracted from ores?
Answer: Metals are extracted from ores by “reduction”, i.e. giving back to the metal atoms the electrons that in the ores they had lost through “oxidation”. Typically but not always this requires elevated temperatures (in blast furnaces provided by burning coke) and the use of materials that accept the electrons and in the process form “slags” (e.g. lime stone in blast furnaces)
Question: In terms of electrons how are metals extracted from ores?
Answer: Metals are extracted from ores by “reduction”, i.e. giving back to the metal atoms the electrons that in the ores they had lost through “oxidation”. Typically but not always this requires elevated temperatures (in blast furnaces provided by burning coke) and the use of materials that accept the electrons and in the process form “slags” (e.g. lime stone in blast furnaces)
Question: What are the metals/minerals that are pre-eminently won in deep mining?
Answer: Noble metals, i.e. gold, silver, platinum, rhodium
Question: Chemically, when a metal is “reduced” from one of its ores, does the metal ions gain or loose electrons?
Answer: Gain
Question: In the Dark and Middle Ages, by what simple method did the Moors gain metallic copper from plentiful copper sulfide ores in Spain?
Answer: They “roasted” (i.e. heated in the open air) copper sulfide ore, thereby oxidizing the ore into copper sulfate CuSO4. They dissolved this in water (yielding a beautiful blue solution) ehich was poured over scrap iron. This causes the copper to plate out on the iron end to dissolve the iron instead.
uestions: The critical difference between metals and non-metals is the manner in which the atoms are bound together.
(a) What are the three basic forms of bonding?
(b) Which is the bonding of metals? How does it work?
(c) In which way is the bonding responsible for the typical metallic properties?
(a) ionic, covalent and metallic
(a) Metallic. In this bonding the outermost electrons (the “conduction electrons”) are shared among the atoms without fixed positions and serve almost like a glue.
(b) In the metallic bonding, therefore, the conduction electrons are highly mobile. As a result a metal readily conducts current, as well as heat, i.e., is a good electrical as well as heat conductor.
True or false: Metals tend to have a tight-packed structure because their ions attract each other.
Answer: false
True or False: The low resistance of metals at low temperatures is called superconductivity
Answer: False.
Question: Unlike metals, insulators are transparent to visible light. Why?
Answer: Because there are no allowed states near the top of the valence band.
An ion is a charged electron.
False
The energy of an electron in a solid is “quantized”.
True
Metals contain “free” electrons.
True
At low temperatures, the Fermi energy is the highest energy an electron can have.
True
At low temperatures, the Fermi energy is the lowest energy an electron can have.
False
The Fermi sphere becomes larger with increasing temperature
False
Insulators tend to be opaque because light interacts with their electrons
False
Sodium is held together by ionic bonds
False
Metals are opaque because light interacts with their electrons
True
Sodium is held together by ionic bonds
False
Metals tend to have a tight-packed structure because their ‘ions’ attract each other
False
Electrons are shared by atoms in covalent bonds
True
Question: At what electron energy is it most likely to find valence electrons in solids?
Answer: At the Fermi energy.
Question: Describe the standard model of a metal.
Answer: The standard model of a metal is that of a crystal lattice structure of ions (ionized atoms) embedded in a “gas” of electrons that have been removed from the individual atoms so as to be shared by all ions and fill all space between them, which assembly of electrons is called a Fermi Gas.
Question: Name and sketch the three types of bonding
Answer: ionic, covalent, and metallic–see drawings in lecture chapter
Question: The free electron gas model explains, above all:
d. why metals are great conductors of electricity and heat
Question: Briefly describe: a) what conduction electrons are, and b) what their function is.
Answer: a) Conduction electrons: The neutral atoms of metals, when in isolation, have 1 to 3 loosely bound electrons in their outer shells called “conduction electrons”. In the solid metal, these conduction electrons are shared among the atoms without fixed positions, and thus are mobile, almost like a gas.
b) The easy mobility of conduction electrons gives metals their good electrical and heat conductivity. Sharing of the conduction electron provides the “metallic bond”.
Question: Why are insulators transparent to visible light?
Answer: Light is absorbed by freely movable electrons, i.e. pre-eminently the conduction electrons of metals, whereas there are no free electrons in insulators. (Technically this is so because in insulators there are no allowed electronic states near the top of the valence band.)
Question: Why does electrical resistance result in heating?
Answer: Because electrons collide with atoms transferring kinetic energy in each collision.
Fill in the blank: An old view of heat was that it was an unusual (imponderable) type of fluid.
This idea was known as the _________________ theory.
Answer: caloric
Part of the genius of human progress is their (our) ability to:

Part of the genius of human progress is their (our) ability to:
(a) violate the First Law of thermodynamics
(b) convert one form of energy into another form for doing usable work.
(c) take advantage of the Second law of thermodynamics by decreasing energy.
(d) build FCC crystals.

(b) convert one form of energy into another form for doing usable work.
Question: Which of the following is the least useful example describing how humans took advantage of the 1st Law of thermodynamics:

(a) Using a water wheel to assist in grinding ores.
(b) Mixing atoms into a state of disorder.
(c) Boiling water to make steam.
(d) Smelting ores.

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(b) Mixing atoms into a state of disorder.
A useful statement of the First Law of thermodynamics is:

(a) The universe is degrading because energy is slowly being destroyed.
(b) The creation of energy from entropy allows processes to occur.
(c) Energy cannot be created but it can be destroyed.
(d) Energy cannot be created or destroyed.
(e) The flow of energy is always from a lower concentration to a higher concentration.

(d) Energy cannot be created or destroyed.
True or false: A modern view is that heat should be viewed as an energy in transit across the boundaries of a material and that the process of heat transfer involves random interactions at the molecular level, involving a temperature difference.
Answer: true
In the poem by John Updike: Ode to Entropy, he states:

“’Heat Death’ will prevail.”

when describing the universe. By this he means:

a) Earth will eventually burn up as the sun expands
b) The universe will dissipate its useful energy
c) Global warming will win out
d) Entropy will reverse when the universe contracts

b) The universe will dissipate its useful energy
Multiple choice: Wooden park benches are more comfortable in winter than metal ones because:

(a) wood has a lower coefficient of thermal expansion than most metals
(b) wood has lower thermal conductivity than metal
(c) wood has higher heat capacity than most metals
(d) wood is anisotropic

(b) wood has lower thermal conductivity than metal
Multiple choice: The risk of thermal shock can be reduced by:

(a) increasing the elastic stiffness
(b) lowering thermal conductivity
(c) decreasing the coefficient of thermal expansion
(d) all of the above

(c) decreasing the coefficient of thermal expansion
Multiple choice: Materials expand upon heating due to the:

(a) increasing kinetic energy of the atoms
(b) symmetry of their potential well
(c) negative coefficient of thermal expansion
(d) decreasing stiffness of the atomic bonds

(a) increasing kinetic energy of the atoms
Multiple choice: Heat capacity refers to:

a) the ability of a material to absorb kinetic energy
(b) the thermal energy storage capacity of a material
(c) the energy required to raise the temperature of an object by one degree
(d) the ability of a material to expand when heated

(b) the thermal energy storage capacity of a material
Multiple choice: As a rule of thumb, the thermal conductivity of a metal is:

(a) much larger than for a non-metal
(b) approximately the same as a non-metal
(c) smaller than for a non-metal

(a) much larger than for a non-metal
Multiple choice: Metals are typically good thermal conductors because:

) they have high heat capacity
(b) the atoms of a metal are closely spaced
(c) they have large numbers of free electrons
(d) none of the above

(c) they have large numbers of free electrons
Task: Glass wool, better known as fiberglas insulation, is commonly used as an insulating material in the walls of homes. It consists of a highly porous tangle of fine glass fibers. Explain why glass wool is a good thermal insulation material.
Answer: Glass is itself a fairly poor conductor of heat (phonon conductor only!), but the large amount of air trapped within the network of fibers is what really cuts down on thermal conduction since air is an extremely poor conductor of heat. The greatest benefit of glass wool is that it suppresses air circulation and thereby eliminates convective heat losses.
Task: Glass wool, better known as fiberglas insulation, is commonly used as an insulating material in the walls of homes. It consists of a highly porous tangle of fine glass fibers. Explain why glass wool is a good thermal insulation material.
Answer: Glass is itself a fairly poor conductor of heat (phonon conductor only!), but the large amount of air trapped within the network of fibers is what really cuts down on thermal conduction since air is an extremely poor conductor of heat. The greatest benefit of glass wool is that it suppresses air circulation and thereby eliminates convective heat losses.
Question: What type of chemical bonding is exhibited by NaCl and why is it stable?
Answer: Ionic bonding. Every Na gives up an outer electron and the Cl atoms accept an extra electron each. Thus there is charge neutrality and a stable electron configuration, while the ions bond due to the coulombic attraction between oppositely charged particles, i.e. between the Na+ and Cl- ions.
Task: Holding a wooden bat in one hand and an aluminum bat in the other outside in the winter, you notice that although the free ends of the two bats are at the same temperature (i.e. , say, 30 F of the still air), the aluminum bat feels much colder. Please explain.
Answer: The aluminum in the metal bat is an excellent thermal conductor (by virtue of its free electrons), and so readily whisks heat from your hand (heat flows from warmer to cooler bodies). On the other hand (literally), the wooden bat is a poor thermal conductor and so the rate of heat loss from your hand is much slower. Thus, although both bats are initially at the same temperature as the ambient air, the metallic one feels colder because of the higher rate of conduction.
Task: Holding a wooden bat in one hand and an aluminum bat in the other outside in the winter, you notice that although the free ends of the two bats are at the same temperature (i.e. , say, 30 F of the still air), the aluminum bat feels much colder. Please explain.
Answer: The aluminum in the metal bat is an excellent thermal conductor (by virtue of its free electrons), and so readily whisks heat from your hand (heat flows from warmer to cooler bodies). On the other hand (literally), the wooden bat is a poor thermal conductor and so the rate of heat loss from your hand is much slower. Thus, although both bats are initially at the same temperature as the ambient air, the metallic one feels colder because of the higher rate of conduction.
Fill in the blank: An old view of heat was that it was an unusual (imponderable) type of fluid.
This idea was known as the _________________ theory.
Answer: caloric
Truer false: A modern view is that heat should be viewed as an energy in transit across the boundaries of a “system” and that the process of heat transfer involves random interactions at the molecular level, involving a temperature difference.
Answer: true
Which metals use metallic bonding?
Iron (Fe), Copper (Cu), Bronze (Cu-Sn)
Name something that uses ionic bonding.
Table Salt (Sodium Cloride NaCl)
Name some things that use covalent bonding.
Diamond and Silicon (Si — used in computer chips)
What is metallic bonding?
ions repel each other electrically, but they are attracted to oppositely charged Fermi gas. The Fermi gas acts to compress the ions and therefore the ions are very closely packed
What is Ionic Bonding?
using the example of table salt, the sodium ions are positively charged and therefore repel each other while the chlorine ions are negatively charged. Therefore the sodium will be attracted to the chlorine and you will have a structer where Na is only surrounded by Cl and vice versa
What is covalent bonding?
Covalent bonding involves the sharing of electrons between atoms
What is a native metal? Name the native metals
Metals found in their metallic form in nature

Copper
Silver
Gold (these are the most important)
Iron can be found natively in meteorites

What is an ore?
Metal containing minerals (rocks)
What is smelting?
Process to obtain metals from ores requiring intense heat and a reducing atmosphere
What is slag?
Lightweight byproduct of smelting which floats on top of the molten metal
What is flux
something that is combined with the ore during the smelting process (creates slag) the flux ensures that the metal is not oxidized and that the impurities will not reduce the usefulness of the metal
What are the seven metals of antiquity
Gold
Copper
Silver
Lead
Tin
Mercury
Iron
What were the eight metals of antiquity and their chemical symbols?
Gold Au
Silver Ag
Copper Cu
Tin Sn
Iron Fe
Lead Pb
Zinc Zn (not included in some lists)
Mercury Hg
What is amalgamation
combining mercury with other metals
How do you make brass? How do you make bronze?
Brass = copper + zinc
Bronze = copper + tin
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