periodic table periodic table with valence electrons

Halite is the mineral name for rock salt, a natural mineral consisting essentially of sodium chloride (NaCl). Together these words combine to mean 'salt former', referencing the fact that halogens form salts when they react with metals. The name 'halogen' is derived from the Greek roots hal- ('salt') and -gen ('to form'). Halogen elements can cross-link to form diatomic molecules with polar covalent single bonds.Ĭhlorine (Cl 2) was the first halogen to be discovered in 1774, followed by iodine (I 2), bromine (Br 2), fluorine (F 2), and astatine (At, discovered last in 1940). When a halogen atom is substituted for a covalently-bonded hydrogen atom in an organic compound, the prefix halo- can be used in a general sense, or the prefixes fluoro-, chloro-, bromo-, or iodo- can be used for specific halogen substitutions. When in the -1 oxidation state, with carbon or nitrogen in organic compounds, the halogens often form single bonds. Therefore, most of the chemical reactions that involve halogens are oxidation-reduction reactions in aqueous solution. Replacing the -ine ending with an -ide ending indicates the presence of halide anions for example, Cl - is named 'chloride.' In addition, halogens act as oxidizing agents-they exhibit the property to oxidize metals. In these compounds, halogens are present as halide anions with charge of -1 (e.g., Cl -, Br -, etc.).

All halogens form Group 1 salts with similar properties. As a general rule, fluorine is the most reactive halogen and astatine is the least reactive. However, halogens readily combine with most elements and are never seen uncombined in nature. The bonds in these diatomic molecules are non-polar covalent single bonds. Halogens form diatomic molecules (of the form X 2, where X denotes a halogen atom) in their elemental states.

Periodic table periodic table with valence electrons