Oxygen is a bi-element compound that chemically combines with other elements to form oxygen . Oxides can be acidic , alkaline , bipolar or neutral in nature. Oxides of metals are generally alkaline and oxides of non-metals are acidic. Names of some oxides 1. Nitrogen dioxide ( NO 2 ) Sodium oxide ( Na 2 O) 3. Potassium oxide ( K 2 O) 4. Phosphorus pentoxide ( P₄O₁₀) 5. Calcium oxide ( CaO)