Early History of Metal Use in Human Culture (L22)

Question 1

what were most metals used for?

Answer 1

ornamental purposes

Question 2

What are the 4 stages of tool making by our ancestors?

Answer 2

1. Oldowan tools - very simple, meant for cutting or chopping
2. Acheulean tools - double edge, more refined appearance
3. Mousterian tools - little more refined, maximized cutting surface
4. Paleolithic tools - more sophisticated and use of a variety of materials

Question 3

what were the preferred rocks for producing the tools made by our ancestors?

Answer 3

composed of silica, in the form of glass and quartz

Question 4

what is the next widespread metal used by humans?

Answer 4

copper

Question 5

What was an early metal that was discovered by stone age humans and what was it used for?

Answer 5

native gold - used for artistic objects of beauty as it was soft and mealleable

Question 6

What were copper weapons used for?

Answer 6

for show of nobility than for use as tools

Question 7

What were 3 major limitations of using copper as tools?

Answer 7

its brittleness and the softness of the metal (couldn’t hold a sharp edge for very long AND the availability of copper

Question 8

what are 2 other metals that could have been used more or less?

Answer 8

silver, iron/nickel alloy

Question 9

what was a major improvement to copper technology?

Answer 9

when it was discovered that copper could be annealed when heated

perimitted stronger tools to be made

Question 10

how did copper become more available?

Answer 10

with the discovery that copper could be smelted from mineral compounds by heating

Question 11

what are 2 reasons why smelting couldn’t have been a result of accidental “cooking” of metal ores in campfires?

Answer 11

the heat generated in a campfire is unlikely to have reached temperatures necessary to allow metals to seperate from the ore

the presence of large amounts of oxygen in a campfire would have readily oxidized any metal that was produced by melting

Question 12

where is it likely that the first smelted ore was produced and why?

Answer 12

In a pottery kiln b/c high temp could be achieved in a kiln

Question 13

how were metals smelted within a kiln?

Answer 13

the oxygen-starved conditions within a kiln would prevent the combination of pure metal with oxygen

also, the presence of fluxes would lower the melting point of minerals within the kiln and ultimately lowering the melting point of the metals

Question 14

when do copper sulphides generally occur?

Answer 14

they occur with sulphides of other metals such as arsenic

Question 15

what was the aresenic later replaced with and why?

Answer 15

Tin

tin lowers the melting point of copper making it easier for metal to be smelted

Question 16

why is bronze moer useful for tools than copper?

Answer 16

it is harder than pure copper and the invention of brass casting made bronze more useful

Question 17

What did smelted iron form rather than liquid droplets like other metals?

Answer 17

formed a spongy solid mass called “bloom”

Question 18

how was purification of iron done?

Answer 18

accomplished by repeated heating and pounding of the bloom

Question 19

what are 3 qualities of pure iron that are undesireable?

Answer 19

softer than bronze
too soft to hold a sharp edge
tends to oxidize (rust)

Question 20

2 main advances in tech that iron has done?

Answer 20

steeling
tempering

Question 21

what is tempering and what does it involve?

Answer 21

an effective method of altering the properties of steel

involves: the quenching (sudden cooling) of hot metal in water (to increase hardness) and reheating (to reduce brittleness)

Question 22

What is Pig Iron?

Answer 22

melted iron being poured into moulds

Question 23

why is it called pig iron?

Answer 23

b/c the molten iron was directed down a central trough with smaller offshoots that led to moulds and this reminded someone of piglets suckling on their mother

Question 24

what did reheating the cast iron (pig iron) do?

Answer 24

drove off the excess carbon, making the product more elastic and malleable for final use