Kids ASK! about Science & Technology
The traditional pencil can be fondly described as the writing instrument encased in a cylindrical wooden casing. The supposedly pencil ‘lead’ was actually made up of graphite mixed with clay and water.
As you know, there are varying blackness when we use different types of pencils, e.g 2B, 2H etc. The blackness of the pencil is dependant on the mixture of the ingredients.
Then you must be asking: “Why is it called lead when the metal, lead, is not part of the ingredient?”
Well, the Romans did write with metallic lead but in 1400, a soft material rock was discovered which led to people to believe it was metallic lead. Pencils were then manufactured from this discovered material. This was finally proved wrong in 1779 when the material was actually discovered to be microcrystalline carbon. This form of carbon was then christened graphite.
Source: Chipman, R. A. (2008). Pencil. Encyclopedia Americana. Retrieved May 26, 2008, from Grolier Online http://ea.grolier.com/cgi-bin/article?assetid=0306920-00
For more amazing facts, here are some recommended library books on minerals and crystals:
Rocks and minerals by Kelly Milner Halls
Publisher: Oxford : Heinemann Library, 2007
Call No.: Y 552 HAL
Minerals by Sally M. Walker
Publisher: Minneapolis, Minn. : Lerner Publications Co., c2007
Call No.: J 549 WAL
Crystals by Connor Dayton
Publisher: New York, N.Y. : PowerKids Press, c2007
Call No.: J 548 DAY
Minerals : from apatite to zinc by Darlene R. Stille
Publisher: Minneapolis, Minn. : Compass Point Books, c2005
Summary: “Explains what minerals are, the elements in minerals, properties of minerals, where minerals are found, and how minerals are used.”
Call No.: J 549 STI
All websites were last accessed on 2 June 2008. Please check the websites’ homepages for the terms and conditions of use. All book summaries were taken from the book descriptions. All images were extracted from www.amazon.com and www.bn.com.
For the availability of the above book titles, please check the library catalogue.
Originally answered by Mr Zulkifli Bin Amin
Posted by Ms Elizabeth Lee
Found this post interesting? What do you think? Post your comments.
If you have a different question, please email to email@example.com instead of sending a comment.