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Historically, graphite was called black lead or plumbago. [ 16 ] [ 48 ] Plumbago was commonly used in its massive mineral form. Both of these names arise from confusion with the similar-appearing lead ores, particularly galena .
[citation needed] Consequently, it was called plumbago (Latin for "lead ore"). [9] [10] Because the pencil core is still referred to as "lead", or "a lead", many people have the misconception that the graphite in the pencil is lead, [11] and the black core of pencils is still referred to as lead, even though it never contained the element lead.
On average, lead makes up 23 parts per million of soil, but the concentration can reach 20000 parts per million (2 percent) near old lead mines. Lead exists in seawater at concentrations of 2 parts per trillion. Lead makes up 1.7 parts per million of the human body by weight. Human activity releases more lead into the environment than any other ...
An alkaline battery (IEC code: L) is a type of primary battery where the electrolyte (most commonly potassium hydroxide) has a pH value above 7. Typically these batteries derive energy from the reaction between zinc metal and manganese dioxide.
The lead-acid battery is a type of rechargeable battery first invented in 1859 by French physicist Gaston Planté. It is the first type of rechargeable battery ever created. Compared to modern rechargeable batteries, lead-acid batteries have relatively low energy density. Despite this, they are able to supply high surge currents.
The adsorption of water reduces the bonding energy between the hexagonal planes of the graphite to a lower level than the adhesion energy between a substrate and the graphite. Because water vapor is a requirement for lubrication, graphite is not effective in vacuum. [4] Because it is electrically conductive, graphite can promote galvanic ...
Treating graphite with strong acids in the presence of oxidizing agents causes the graphite to oxidise. Graphite bisulfate, [C 24] + [HSO 4] −, is prepared by this approach using sulfuric acid and a little nitric acid or chromic acid. The analogous graphite perchlorate can be made similarly by reaction with perchloric acid. [clarification needed]
Mercury batteries use either pure mercury(II) oxide (HgO)—also called mercuric oxide—or a mixture of HgO with manganese dioxide (MnO 2) as the cathode.Mercuric oxide is a non-conductor, so some graphite is mixed with it; the graphite also helps prevent collection of mercury into large droplets.