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Naturally occurring tungsten consists of four stable isotopes (182 W, 183 W, 184 W, and 186 W) and one very long-lived radioisotope, 180 W. Theoretically, all five can decay into isotopes of element 72 by alpha emission, but only 180 W has been observed to do so, with a half-life of (1.8 ± 0.2) × 10 18 years; [33] [34] on average, this yields ...
e. The chemical elements can be broadly divided into metals, metalloids, and nonmetals according to their shared physical and chemical properties. All elemental metals have a shiny appearance (at least when freshly polished); are good conductors of heat and electricity; form alloys with other metallic elements; and have at least one basic oxide.
The periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows (" periods ") and columns (" groups "). It is an icon of chemistry and is widely used in physics and other sciences. It is a depiction of the periodic law, which states that when the elements are arranged in order ...
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable isotope is 23 Na. The free metal does not occur in nature and must be prepared from compounds. Sodium is the sixth most abundant element in the Earth's crust and exists in numerous minerals such as feldspars, sodalite, and halite (NaCl).
Einsteinium is a synthetic chemical element; it has symbol Es and atomic number 99. It is named after Albert Einstein and is a member of the actinide series and is the seventh transuranium element. Einsteinium was discovered as a component of the debris of the first hydrogen bomb explosion in 1952. Its most common isotope, einsteinium-253 (253 ...
Biological roles of the elements. 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]
A chemical element is a chemical substance that cannot be broken down into other substances by chemical reactions. The basic particle that constitutes a chemical element is the atom. Elements are identified by the number of protons in their nucleus, [1] known as the element's atomic number. [2] For example, oxygen has an atomic number of 8 ...