Why do pencils loose their conductivity?

Okay so pencils are made up of graphiteand clay. Graphite is the conductor. Also people complain that pencils get SMUGED.

1) How can the lead get smuged after its on the chip? Its covered, nothing rubbing.

2) Why does graphite lose its conductivity over time?

i believe that there is nothing to bind the grafite together and when applied to the chip it is little more than dust.....

there is an air space between the chip and hs ;D

that weak hu? Even softones?

Anyone know where to purchase a defogger kit online for really cheap? I keep seeing $16+ ...ouch!

Also, for defogger's, why not just use a toothpick and draw the lines, then no need for biz card and alcohol to clean up

i would suggest going to a electronic store and having them solder the l1- it is a one time permanent solution and you are guarenteed a good connection, A place did mine for $20.00 cash in about 5 minutes

Go to most any auto parts store (Napa,Auto Zone,Discount Auto) You'll find what you want there for around 7$.I used it and it works great and as far as I know its permenant. Use a needle and get a good magnifying glass,i used a 10X jewlers. Just dont short the bridges.

kat (Apr 15, 2001 06:00 p.m.):
i believe that there is nothing to bind the grafite together and when applied to the chip it is little more than dust.....

there is an air space between the chip and hs ;D

Click to expand...

indeed you are correct kat. Graphite(one form of carbon) is held together by london dispersion forces which are extremely weak forces. They are the same ones that hold butter molecules together and all it takes to overcome those forces is to put it on top of a warm piece of bread. Plus graphite is only a semiconductor so it does not even conduct as well in the first place. Also, i am not too sure about this, but carbon may not like to let go of the electrons it gets vs. say copper, and after a while it just keeps the elctrons it has and will not transfer them. This is my best guess for this problem and is getting to the brink of my knowledge in chemistry.