Introduction:
Oxides are compounds formed by the combination of oxygen with other elements. They can be classified into three categories based on their acidity or basicity: acidic, basic, and amphoteric oxides. The nature of these oxides depends on the electronegativity of the elements involved.

Explanation:
1. Acidic Oxides:
Acidic oxides are oxides that react with water to form acids. They typically contain nonmetals and have high electronegativity. These oxides tend to donate protons (H+) to water molecules, resulting in the formation of acidic solutions. Examples of acidic oxides include sulfur dioxide (SO2) and carbon dioxide (CO2).

2. Basic Oxides:
Basic oxides are oxides that react with water to form bases. They usually consist of metals and have low electronegativity. These oxides tend to accept protons (H+) from water molecules, leading to the formation of basic solutions. Examples of basic oxides include sodium oxide (Na2O) and calcium oxide (CaO).

3. Amphoteric Oxides:
Amphoteric oxides are oxides that can exhibit both acidic and basic properties. They can react with both acids and bases, depending on the conditions. The amphoteric nature of these oxides is due to the presence of elements with intermediate electronegativity. Examples of amphoteric oxides include aluminum oxide (Al2O3) and zinc oxide (ZnO).

Sequence of Electronegativity:
The sequence of electronegativity for the given oxides, A, B, and C, can be determined based on their nature as acidic, basic, or amphoteric.

- If oxide A is acidic, it means it contains a nonmetal with high electronegativity.
- If oxide B is basic, it means it contains a metal with low electronegativity.
- If oxide C is amphoteric, it means it contains an element with intermediate electronegativity.

Therefore, the sequence of electronegativity would be:
A > C > B

Conclusion:
In summary, the nature of oxides can be classified as acidic, basic, or amphoteric based on their reaction with water. The acidity or basicity of an oxide depends on the electronegativity of the elements involved. Oxides with high electronegativity tend to be acidic, oxides with low electronegativity tend to be basic, and oxides with intermediate electronegativity tend to be amphoteric. The given sequence of electronegativity for the oxides A, B, and C is A > C > B.