Pencil #41, 46, 25

Pencil

#41- An element that is used as a lubricant
- The element graphite is widely used as a lubricant. Graphite is found in pencils.
-Cite: Notes

#46- An element that has more thean one isotope and can exist as an ion.
-Carbon has more then one isotope and can be an ion. Carbon is found in graphite which is found in pencils.
-Cite: http://answers.yahoo.com/question/index?qid=20071129180214AArpmJE

#25- A sample of matter containing a radioactive element. Give decay equation.
-The lead in pencils is a radioactive element. Its decays in 21 years and its equation is 82(210)Pb -> 80(206)Hg + 2(4)He
Cite: http://wiki.answers.com/Q/What_is_the_nuclear_decay_equation_for_lead-210
      - http://www.buzzle.com/articles/list-of-radioactive-elements.html