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 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- 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 ra 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 ra p h i t e > .

" N a t u ra 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 > .

Pe 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 Pe n c i l s . " Pe n c i l , Pe n c i l s , B u y

Pe 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 > .