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A LED is a long-lived light source, but certain mechanisms can cause slow loss of efficiency of the device or sudden failure. The wavelength of the light emitted is a function of the band gap of the semiconductor material used; materials such as gallium arsenide , and others , with various trace doping elements , are used to produce different ...
Lead (/ l ɛ d /) is a chemical element; it has symbol Pb (from Latin plumbum) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to ...
The lead wire is a coated copper wire, a tinned copper wire or another electrically conductive wire used to connect two locations electrically. In electronics, a lead (/ ˈ l iː d /) or pin is an electrical connector consisting of a length of wire or a metal pad (surface-mount technology) that is designed to connect two locations electrically.
Lead sesquioxide, Pb 2 O 3, which is a lead (II,IV) oxide as well (lead(II) metaplumbate(IV) [Pb 2+][PbO 2− 3]), reddish yellow Pb 12 O 19 , monoclinic, dark-brown or black crystals The so-called black lead oxide , which is a mixture of PbO and fine-powdered Pb metal and used in the production of lead–acid batteries .
Lead (82 Pb) has four observationally stable isotopes: 204 Pb, 206 Pb, 207 Pb, 208 Pb. Lead-204 is entirely a primordial nuclide and is not a radiogenic nuclide.The three isotopes lead-206, lead-207, and lead-208 represent the ends of three decay chains: the uranium series (or radium series), the actinium series, and the thorium series, respectively; a fourth decay chain, the neptunium series ...
[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.
Lead and cadmium were found in a majority of the protein powders that were tested. There is no safe level of lead, which has been linked to developmental disorders and high blood pressure.
Simple LED (Light Emitting Diode) circuit diagram. In electronics, an LED circuit or LED driver is an electrical circuit used to power a light-emitting diode (LED). The circuit must provide sufficient current to light the LED at the required brightness, but must limit the current to prevent damaging the LED.