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Carl Wilhelm Scheele (German:, Swedish: [ˈɧêːlɛ]; 9 December 1742 – 21 May 1786 [2]) was a German Swedish [3] pharmaceutical chemist.. Scheele discovered oxygen (although Joseph Priestley published his findings first), and identified molybdenum, tungsten, barium, nitrogen, and chlorine, among others.
Glucose is a sugar with the molecular formula C 6 H 12 O 6.It is overall the most abundant monosaccharide, [4] a subcategory of carbohydrates.It is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight.
Calcium is the only element with two primordial doubly magic isotopes. The experimental lower limits for the half-lives of 40 Ca and 46 Ca are 5.9 × 10 21 years and 2.8 × 10 15 years respectively. [30] Apart from the practically stable 48 Ca, the longest lived radioisotope of calcium is 41 Ca.
Scheele showed that scheelite (then called tungsten) was a salt of calcium with a new acid, which he called tungstic acid. The Elhuyars obtained tungstic acid from wolframite and reduced it with charcoal, naming the element "volfram". [1] [87] Since that time both names, tungsten and wolfram, have been used depending on language. [1]
Friedrich Miescher (1844–1895) discovered a substance he called "nuclein" in 1869. Somewhat later, he isolated a pure sample of the material now known as DNA from the sperm of salmon, and in 1889 his pupil, Richard Altmann, named it "nucleic acid". This substance was found to exist only in the chromosomes.
The importance of his discovery was not apparent until Albrecht Kossel (a German physiologist specializing in the physiological chemistry of the cell and its nucleus and of proteins) researched the chemical structure of nuclein. [8] Miescher is also known for demonstrating that carbon dioxide concentrations in blood regulate breathing. [1]
The heaviest discovery to date, element 118 oganesson, was made using a beam of calcium isotope 48 particles. Calcium 48, with its definitive 20 protons plus 28 neutrons, is a common and very ...
The number of protons in an atom (which Rutherford called the "atomic number" [27] [28]) was found to be equal to the element's ordinal number on the periodic table and therefore provided a simple and clear-cut way of distinguishing the elements from each other. The atomic weight of each element is higher than its proton number, so Rutherford ...