hapetusasteilla

Hapetusasteilla, often translated as oxidation states, are a bookkeeping concept used in chemistry to track the hypothetical charge an atom would have if all its bonds to different atoms were purely ionic. It is a convention, not a literal charge. The sum of the oxidation states of all atoms in a neutral molecule must be zero. For a polyatomic ion, the sum must equal the charge of the ion. There are rules to assign oxidation states. The oxidation state of an element in its elemental form is always zero. For monatomic ions, the oxidation state is equal to the charge of the ion. Oxygen in most compounds has an oxidation state of -2, except in peroxides where it is -1 and when bonded to fluorine. Hydrogen typically has an oxidation state of +1 when bonded to nonmetals and -1 when bonded to metals. Alkali metals (Group 1) always have an oxidation state of +1, and alkaline earth metals (Group 2) always have +2 in their compounds. Halogens (Group 17) usually have an oxidation state of -1, unless bonded to a more electronegative element like oxygen or another halogen higher up in the group. These assignments are crucial for understanding redox reactions, where electrons are transferred between species, leading to changes in oxidation states. Assigning oxidation states helps to identify which species is oxidized (loses electrons, oxidation state increases) and which is reduced (gains electrons, oxidation state decreases).