Resultado de búsqueda
Hace 5 días · Potassium is a chemical element; it has symbol K (from Neo-Latin kalium) and atomic number 19. It is a silvery white metal that is soft enough to easily cut with a knife. [8] Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure.
Hace 4 días · Antimony is a silvery, lustrous gray metalloid with a Mohs scale hardness of 3, which is too soft to mark hard objects. Coins of antimony were issued in China's Guizhou province in 1931; durability was poor, and minting was soon discontinued. [10] Antimony is resistant to attack by acids.
Hace 5 días · Arsenic is the 53rd most abundant element in the Earth's crust, comprising about 1.5 parts per million (0.00015%). [43] Typical background concentrations of arsenic do not exceed 3 ng/m 3 in the atmosphere; 100 mg/kg in soil; 400 μg/kg in vegetation; 10 μg/L in freshwater and 1.5 μg/L in seawater. [44]
Hace 2 días · In Homeric and Ionic Greek, he was known as Áïdēs. Other poetic variations of the name include Aïdōneús (Ἀϊδωνεύς) and the inflected forms Áïdos (Ἄϊδος, gen.), Áïdi (Ἄϊδι, dat.), and Áïda (Ἄϊδα, acc.), whose reconstructed nominative case *Áïs (* Ἄϊς) is, however, not attested.
Hace 5 días · Technetium is a chemical element; it has symbol Tc and atomic number 43. It is the lightest element whose isotopes are all radioactive. Technetium and promethium are the only radioactive elements whose neighbours in the sense of atomic number are both stable. All available technetium is produced as a synthetic element.
Hace 2 días · Ramsay suggested the name xenon for this gas from the Greek word ξένον xénon, neuter singular form of ξένος xénos, meaning 'foreign(er)', 'strange(r)', or 'guest'. In 1902, Ramsay estimated the proportion of xenon in the Earth's atmosphere to be one part in 20 million.
Hace 4 días · Beryllium is a chemical element; it has symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form minerals. Gemstones high in beryllium include beryl ( aquamarine, emerald, red beryl) and chrysoberyl.
