Mechanical pencil Mechanical pencil A mechanical pencil (US English) or propelling pencil (UK English), also clutch pencil, is a pencil with a replaceable and mechanically extendable solid pigment core called a "lead" . The lead, often made of graphite, is not bonded to the outer casing, and can be mechanically extended as its point is worn away. Other names include microtip pencil, automatic pencil, drafting pencil, technical pencil, click pencil, pump pen, pump pencil, leadholder, pen pencil (Indian English), and lead pencil (Bangladeshi and American English). Mechanical pencils are used to provide lines of constant width without sharpening in technical drawing and
Lead(II) thiocyanate has not been confirmed by other sources than the author of this article, experiments show that even if there is no precipitation of lead(II) thiocyanate in the solution, crystals of the salt may form. Lead(II) thiocyanate can be formed from the acidification of Lead Nitrate Pb(NO) with nitric acid (HNO) in the presence of Thiocyanic acid (HSCN) Lead(II) thiocyanate may be made by reacting lead(II) acetate (Pb(CHCOO)) solved in water with either potassium thiocyanate (KSCN) or ammonium thiocyanate (NHSCN), thus causing a white precipitation of solid lead(II) thiocyanate. Ion reaction: When exposed to UV or visible light lead thiocyanate will