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Gallium is one of the four non-radioactive metals (with caesium, rubidium, and mercury) that are known to be liquid at, or near, normal room temperature. Of the four, gallium is the only one that is neither highly reactive (as are rubidium and caesium) nor highly toxic (as is mercury) and can, therefore, be used in metal-in-glass high ...
Atmospheric circulation is the large-scale movement of air through the troposphere, and the means (with ocean circulation) by which heat is distributed around Earth. The large-scale structure of the atmospheric circulation varies from year to year, but the basic structure remains fairly constant because it is determined by Earth's rotation rate ...
The abundance of the chemical elements is a measure of the occurrences of the chemical elements relative to all other elements in a given environment. Abundance is measured in one of three ways: by mass fraction (in commercial contexts often called weight fraction), by mole fraction (fraction of atoms by numerical count, or sometimes fraction of molecules in gases), or by volume fraction.
A chemical element is a chemical substance whose atoms all have the same number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8, meaning each oxygen atom has 8 protons in its nucleus.
The former (which has two forms, one purple and one green) [72] is a rare example of thorium in the formal +3 oxidation state; [73] a formal +2 oxidation state occurs in a derivative. [74] The chloride derivative [Th(C 5 H 5) 3 Cl] is prepared by heating thorium tetrachloride with limiting KC 5 H 5 used (other univalent metal cyclopentadienyls ...
Tin in combination with other elements forms a wide variety of useful alloys. Tin is most commonly alloyed with copper. Pewter is 85–99% tin, [97] and bearing metal has a high percentage of tin as well. [98] [99] Bronze is mostly copper with 12% tin, while the addition of phosphorus yields phosphor bronze.
The fixed rate for a 15-year mortgage is 5.99%, up 28 basis points from last week's average 5.71%. These figures are lower than a year ago, when rates averaged 7.76% for a 30-year term and 7.03% ...
A large fraction of the chemical elements that occur naturally on the Earth's surface are essential to the structure and metabolism of living things. Four of these elements (hydrogen, carbon, nitrogen, and oxygen) are essential to every living thing and collectively make up 99% of the mass of protoplasm. [1]