what is a pencil made from???
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What is a pencil made from???. Where do they come from??? By, Mr. Howard Period 2. Cool Pencil History Factoids!. Ancient Romans called scribes used to use rods of metal to write on papyrus. First Mass produced pencils were in Germany, in 1662. . Oldest Known Wood- Cased Pencil. - PowerPoint PPT PresentationTRANSCRIPT
What is a pencil made from???
Where do they come from???
By, Mr. Howard Period 2
Cool Pencil History Factoids!
• Ancient Romans called scribes used to use rods of metal to write on papyrus.
• First Mass produced pencils were in Germany, in 1662.
Oldest Known Wood- Cased Pencil
MATERIALS FOUND IN A PENCIL• A PENCIL is made from three main
ingredients:
– Synthetic Rubber. This is a COMPOUND. It is made from fossil fuels (hydrocarbons), so it contains Carbon and Hydrogen.
– Incense Cedar Wood. This is a MIXTURE. It has “cellulose” fibers, formula C6H10O5.
– Graphite (they don’t use lead anymore; toxic!). Graphite is an ELEMENT, formula C (pure carbon)
Chemical and Physical PropertiesRubber Eraser (HydroCarbon)Density: 0.91 g/cm3
Melting Point: -183 C
Boiling Point: -164 C
Normal State: Gas
(Must be mixed with
other polymers to make
it into a solid).
Soluble? Not in water
Flammable? VERY!!
• Incense Cedar Wood (Cellulose- C6H10O5)
Density: 0.38 g/cm3
Melting Point: None
Boiling Point:None
Normal State: Solid
Soluble? NO
Flammable? Yes!
Graphite (pure carbon)Density: 2.09 g/cm3
Melting Point: 3500 deg C
Boiling Point: 3600 deg C
Normal State: SOLID
Soluble? Not in water.
Flammable? Generally no,
only at EXTREMELY high
temps!
Where does the “RUBBER” of a pencil come from?
• Hydrocarbons are “fossil fuels” (dead dinosaurs!), so we get them from the ground.
• Most comes from Middle East and domestic sources.
• Environmental concerns- factory pollution from processing the oil, and oil spills.
Where does the WOOD of a pencil come from?
• Most cedar wood is harvested in the Pacific Northwest (our home!!).
• One concern is clear-cutting forests destroys habitat for other species and contributes to erosion which damages salmon streams.
Where does the GRAPHITE of a pencil come from?
• Graphite is mined around the world in Italy, Finland, and the US (New Jersey, Colorado, Arizona).
• It is extracted from open pit mines.
• Open pit mining destroys large areas of land, and creates toxic water and waste products.
Works Cited
" G r a p h i t e . " W i k i p e d i a , t h e F r e e E n c y c l o p e d i a . We b . 2 3 J a n . 2 0 1 2 .
< h tt p : / /e n .w i k i p e d i a . o r g / w i k i / G r a p h i t e > .
" N a t u r a l R u b b e r. " W i k i p e d i a , t h e F r e e E n c y c l o p e d i a . We b . 2 4 J a n . 2 0 1 2 .
< h tt p : / /e n .w i k i p e d i a . o r g / w i k i / R u b b e r > .
P e n c i l s , C a t e g o r y C a r p e n t e r. " T h e S t o r y o f P e n c i l s . " Pe n c i l , P e n c i l s , B u y
P e n c i l s . We b . 2 1 J a n . 2 0 1 2 . < h tt p : / / w w w. p e n c i l s . c o m / s t o r y- p e n c i l s > .