The elements that usually form oxides with the general formula M₂O₃ belong to Group 13 of the periodic table, also known as the Boron group.

Here's why:

* Valence electrons: Group 13 elements have three valence electrons.

* Oxidation state: They typically lose these three electrons to achieve a stable noble gas configuration, resulting in a +3 oxidation state.

* Formation of M₂O₃: To form a neutral oxide, two metal atoms (M) with a +3 charge each combine with three oxygen atoms (O) with a -2 charge, leading to the formula M₂O₃.

Examples of Group 13 oxides with M₂O₃ formula:

* Aluminum oxide (Al₂O₃)

* Gallium oxide (Ga₂O₃)

* Indium oxide (In₂O₃)

* Thallium(III) oxide (Tl₂O₃)

Note: While some elements in other groups may form oxides with the M₂O₃ formula under specific conditions, Group 13 elements consistently exhibit this characteristic due to their electronic configuration.