Hapetusasteista

Hapetusasteista, meaning oxidation states in Finnish, refers to the hypothetical charge an atom would have if all of its bonds to atoms of different elements were 100% ionic. It is a useful concept in chemistry for tracking electron transfer in redox reactions. The oxidation state of an atom in a molecule or ion is assigned by a set of rules. For example, the oxidation state of an element in its elemental form is always zero. In compounds, the oxidation state of oxygen is typically -2, except in peroxides where it is -1 and when bonded to fluorine where it can be positive. Alkali metals (Group 1) almost always have an oxidation state of +1, and alkaline earth metals (Group 2) have an oxidation state of +2. Hydrogen typically has an oxidation state of +1 when bonded to nonmetals and -1 when bonded to metals. The sum of the oxidation states of all atoms in a neutral molecule must equal zero, and in a polyatomic ion, the sum must equal the charge of the ion. Understanding oxidation states helps predict the products of chemical reactions and balance redox equations.