Pencil Pencil A pencil is an implement for writing or drawing constructed of a narrow, solid pigment core inside a protective casing which prevents the core from being broken and/or from leaving marks on the user’s hand during use. Pencils create marks by physical abrasion, leaving behind a trail of solid core material that adheres to a sheet of paper or other surface. They are distinct from pens, which instead dispense liquid or gel ink onto the surface being marked. Most pencil cores are made of graphite powder mixed with a clay binder. Graphite pencils (traditionally known as 'lead pencils') are
Lead conducted on how to remove lead from biosystems by biological means: Fish bones are being researched for their ability to bioremediate lead in contaminated soil. The fungus "Aspergillus versicolor" is effective at removing lead ions. Several bacteria have been researched for their ability to remove lead from the environment, including the sulfate-reducing bacteria "Desulfovibrio" and "Desulfotomaculum", both of which are highly effective in aqueous solutions. Lead Lead is a chemical element with symbol Pb (from the Latin "plumbum") and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and