A cation is formed.
Sodium ion exist in water as the product of a dissociation; sodium (metal) react violently with water
A base is formed from a metal reacting with oxygen to form a metal oxide. Then it reacts with water to form a base that will disociate in water to produce hydroxide ions.
An oxygen atom can only be oxidized by some element with an equal or higher electronegativity. So, oxygen can be oxidized by fluorine (e.g., OF2) or by another oxygen atom (e.g., O2).
Water is formed when a positively charged hydrogen atom reacts with a hydroxide ion. Hydride ions react with water to form hydrogen.
O2- is an oxide ion which reacts with metal to form oxides of the metal. For example: MgO, Na2O
Mg2+
Mg2+
Hydroxonium H3O+ ion is formed.
Mg2+
Fluoride is an ion formed by the nonmetal fluorine.
A hydrogen ion (H+)
Fluoride is the ion formed by the element fluorine, which is a non-metal.