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Lead (pronounced "led") 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.
Lead is obtained from its ores by a method used with many metals. First, the ore is roasted (heated in air). Roasting, also called smelting, converts the ore to a compound of lead and oxygen, lead oxide (PbO 2 ). Lead oxide is then heated with charcoal (pure carbon). The carbon takes oxygen away from the lead oxide.
Lead (pronunciation: LED) is a soft, malleable, and ductile element having a high corrosion resistance, denoted by the chemical symbol Pb. A poor conductor of electricity, it slowly forms a dull coating when exposed to air [1].
Fire can occur in the absence of atmospheric oxygen when fuels are mixed with chemical oxidizers. Many chemical oxidizers contain readily released oxygen. Ammonium nitrate fertilizer (NH 4 NO 3 ), potassium nitrate (KNO 3 ), and hydrogen peroxide (H 2 O 2 ) are examples.
Element Lead (Pb), Group 14, Atomic Number 82, p-block, Mass 207.2. Sources, facts, uses, scarcity (SRI), podcasts, alchemical symbols, videos and images.
22 Νοε 2024 · Lead, a soft, silvery white or grayish metal in Group 14 (IVa) of the periodic table. Lead is very malleable, ductile, and dense and is a poor conductor of electricity. Known in antiquity and believed by the alchemists to be the oldest of metals, lead is highly durable and resistant to corrosion.
18 Ιουλ 2024 · Fire is the result of a chemical reaction called combustion. At a certain point in the combustion reaction, called the ignition point, flames are produced. Ordinarily, flames consist primarily of carbon dioxide, water vapor, oxygen, and nitrogen. In the usual combustion reaction, a carbon-based fuel burns in air (oxygen).
