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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 ...
t. e. 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 ]
Hydrogen is a chemical element; it has symbol H and atomic number 1. It is the lightest element and, at standard conditions, is a gas of diatomic molecules with the formula H2, sometimes called dihydrogen, [ 11 ] but more commonly called hydrogen gas, molecular hydrogen or simply hydrogen. It is colorless, odorless, [ 12 ] non-toxic, and highly ...
Oxygen is the third most abundant chemical element in the universe, after hydrogen and helium.[67] About 0.9% of the Sun's mass is oxygen.[18] Oxygen constitutes 49.2% of the Earth's crustby mass[68]as part of oxide compounds such as silicon dioxideand is the most abundant element by mass in the Earth's crust.
Not long after, Spanish chemists Juan José and Fausto d’Elhuyar y de Suvisa conducted follow-up experiments that successfully isolated tungsten, described in a paper published in 1783. The ...
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 ...
Aluminium (or aluminum in North American English) is a chemical element; it has symbol Al and atomic number 13. Aluminium has a density lower than that of other common metals, about one-third that of steel. It has a great affinity towards oxygen, forming a protective layer of oxide on the surface when exposed to air.
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).