Scandium oxide, also known as scandate, is usually a white or off-white powder. It is a crystalline solid that can form a variety of crystal structures, the most common being the cubic structure. In its pure form, scandium oxide is often used in ceramics, phosphors, and as a catalyst for various chemical reactions. When exposed to air, it absorbs moisture, which may slightly affect its appearance.
Scandium oxide (Sc2O3) is generally considered insoluble in water. It is not soluble in water or most organic solvents. However, it can react with strong acids and bases to form soluble scandium salts. For example, when treated with hydrochloric acid, scandium oxide can dissolve to form scandium chloride. In summary, while scandium oxide is insoluble in water, it can be dissolved in certain acidic or alkaline solutions.