Saturday, March 7, 2020

10 Lead Element Facts (Pb or Atomic Number 82)

10 Lead Element Facts (Pb or Atomic Number 82) Lead is a heavy metal you encounter in everyday life in solder, stained glass windows, and possibly your drinking water. Here are 10 lead element facts. Fast Facts: Lead Element Name: LeadElement Symbol: PbAtomic Number: 82Atomic Weight: 207.2Element Category: Basic Metal or Post-Transition MetalAppearance: Lead is a metallic gray solid at room temperature.Electron Configuration:  [Xe] 4f14  5d10  6s2  6p2Oxidation State: The most common oxidation state is 2, followed by 4. The 3, 1, 1-, 2-, and 4- states also occur. Interesting Lead Element Facts Lead has atomic number 82, which means each lead atom has 82 protons. This is the highest atomic number for the stable elements. Natural lead consists of a mixture of 4 stable isotopes, although radioisotopes also exist. The element name lead comes from the Anglo-Saxon word for the metal.  Its chemical symbol is Pb, which is based on the word plumbum, the old Latin name for lead.Lead is a considered a basic metal or post-transition metal. It is a shiny blue-white metal when freshly cut, but oxidizes to a dull gray in air. It is a shiny chrome-silver when melted. While lead is dense, ductile, and malleable like many other metals, several of its properties are not what one would consider metallic. For example, the metal has a low melting point (327.46  oC)  and is a poor conductor of electricity.Lead is one of the metals that was known to ancient man. It is sometimes called the first metal (although the ancients also knew gold silver, and other metals). Alchemists associated the metal with the planet Saturn and quested for a way to transmute lead into gold. Over half the lead produced today is used in lead-acid car batteries. While lead does occur (rarely) in nature in its pure form, most of the lead produced today comes from recycled batteries. Lead is found in the mineral galena (PbS) and ores of copper, zinc, and silver.  Lead is highly toxic. The element primarily affects the central nervous system. It is particularly dangerous to babies and children, where lead exposure can stunt development. Lead is a cumulative poison. Unlike many toxins, there really is no safe exposure level to lead, even though it is present in many common materials.Lead is the only metal which exhibits zero Thomson effect. In other words, when an electrical current is passed through a sample of lead, heat is neither absorbed nor released.While modern scientists can readily distinguish most elements, it used to be difficult to tell lead and tin apart because the two metals share so many similar properties. So, for a long time the two elements were considered to be different forms of the same metal. The ancient Romans referred to lead as plumbum nigrum, which means black lead. They called tin plumbum candidum, which means bright lead. Wood pencils have never actually contained lead, even though lead is soft enough it could be used for writing. Pencil lead is a type of graphite the Romans called  plumbago, which means act for lead. The name stuck, even though the two materials are different. Lead is, however, related to graphite. Graphite is a form or allotrope of carbon. Lead belongs to the carbon family of elements.There are countless uses for lead. Because of its high corrosion resistance, the ancient Romans used it for plumbing. While this sounds like a dangerous practice, hard water forms scale inside pipes, lessening exposure to the toxic element. Even in modern times, lead solder has been common for welding plumbing fixtures. Lead has been added to gasoline to reduce engine knock, to face paints and paints used for toys and buildings, and even in cosmetics and foods (in the past) to add a sweet flavor. It is used to make stained glass, leaded crystal, fishing sinkers, radiation shields, bullets, scuba weig hts, roofing, ballasts, and statues. While once common as a paint additive and pesticide, lead compounds are less commonly used now because of their lingering toxicity. The sweet taste of the compounds makes them attractive to children and pets. The abundance of lead in the Earths crust is  14 parts per million by weight. The abundance in the solar system is  10 parts per billion by weight.

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