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Lead-208 has 126 neutrons, another magic number, which may explain why lead-208 is extraordinarily stable. [39] With its high atomic number, lead is the heaviest element whose natural isotopes are regarded as stable; lead-208 is the heaviest stable nucleus.
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 ...
The gaps at Z = 82, 114, 120, and 126 correspond to shell closures, [20] which have particularly stable configurations and thus result in more stable nuclei. [ 21 ]
The World Health Organization (WHO) specifically notes that there is "no known safe blood lead concentration," and that even blood lead concentrations as low as 3.5 µg/dL (micrograms per ...
Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver. [5] Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms.
Variation is a characteristic of language: there is more than one way of saying the same thing in a given language. Variation can exist in domains such as pronunciation (e.g., more than one way of pronouncing the same phoneme or the same word), lexicon (e.g., multiple words with the same meaning), grammar (e.g., different syntactic constructions expressing the same grammatical function), and ...
In the lead actor category, David Niven has held the shortest performance record since 1959 when he won for Separate Tables after appearing for just 23 minutes and 39 seconds.
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 ...