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What is a pencil made from??? Where do they come from??? By, Mr. Howard Period 2.

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Presentation on theme: "What is a pencil made from??? Where do they come from??? By, Mr. Howard Period 2."— Presentation transcript:

1 What is a pencil made from??? Where do they come from??? By, Mr. Howard Period 2

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 Ancient Romans called scribes used to use rods of metal to write on papyrus. First Mass produced pencils were in Germany, in Oldest Known Wood- Cased Pencil

3 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 C 6 H 10 O 5. – Graphite (they don’t use lead anymore; toxic!). Graphite is an ELEMENT, formula C (pure carbon) 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 C 6 H 10 O 5. – Graphite (they don’t use lead anymore; toxic!). Graphite is an ELEMENT, formula C (pure carbon)

4 Chemical and Physical Properties Rubber 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- C 6 H 10 O 5 ) 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!

5 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.

6 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. 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.

7 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.

8 "Graphite." Wikipedia, the Free Encyclopedia. Web. 23 Jan "Natural Rubber." Wikipedia, the Free Encyclopedia. Web. 24 Jan Pencils, CategoryCarpenter. "The Story of Pencils." Pencil, Pencils, Buy Pencils. Web. 21 Jan


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