Carbon, Cedar and a Global Market: teacher key

How Pencils Are Made, grade 12 edition, written for 12th grade and up. Why a pencil's lead was never lead, how a single sheet of carbon rolls into a nanotube, and how the pencil fits into a world graphite market.

Read the book. Print this page for the key.

Questions and answers

1. What do poison centers say about pencil graphite and real lead?
   • Not to confuse them (answer)
   • They are the same
   • Graphite is more toxic
2. Why do accounts of Conté's invention disagree on dates?
   • They count different steps, such as the request and the patent (answer)
   • Conté lived twice
   • The patent was lost
3. Which was not on the list of main U.S. graphite uses in 2025?
   • Batteries
   • Pencils (answer)
   • Brake linings
4. What can a graphite sheet rolled into a circle form?
   • A carbon nanotube (answer)
   • A diamond
   • A ferrule
5. What does extrusion mean in a pencil factory?
   • Pushing a material through a mold (answer)
   • Painting wood
   • Cutting a slat

Words

• nanotube: carbon tube
• plumbago: old name
• extrusion: pushing through
• amorphous: without shape