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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 air. Lead has the highest atomic number of any stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements.
Tarnished lead (left) and shiny lead (right) Compounds of lead exist with lead in two main oxidation states: +2 and +4. The former is more common. Inorganic lead(IV) compounds are typically strong oxidants or exist only in highly acidic solutions. [1] Red α-PbO and yellow β-PbO The mixed valence oxide Pb 3 O 4 Black PbO 2 which is a strong ...
Tarnish is a thin layer of corrosion that forms over copper, brass, aluminum, magnesium, neodymium and other similar metals as their outermost layer undergoes a chemical reaction. [1] Tarnish does not always result from the sole effects of oxygen in the air.
Older pewters with higher lead content are heavier, tarnish faster, and their oxidation has a darker, silver-gray color. [10] Pewters containing lead are no longer used in items that will come in contact with the human body (such as cups, plates, or jewelry), due to the toxicity of lead. Modern pewters are available that are completely free of ...
2. Baby Food. One might think that a product advertised for infants and young children would be safe to eat. Alas, it's shocking how much food marketed to kids contains lead.
What does the age of my home have to do with lead risk? The U.S. banned lead-based paints for residential use in 1978. Homes or apartments built before then, and especially in mid-century or ...
Tin-lead solders (Sn50Pb50, Sn60Pb40, Sn63Pb37) can be conditionally used when the apparatus is not to be baked and operating temperatures aren't elevated (lead tends to outgas). A better choice for vacuum systems is the tin-silver eutectic, Sn95Ag5 (Sn-Ag eutectic is actually 96.5-3.5); its melting point of 230 °C (446 °F) allows bakeout up ...
"Lead can be damaging to the developing brain," Calello says. "While adults can have effects from excess lead exposure as well, the effects are more severe in children and occur at lower levels."