👉 A trioxide is a type of compound consisting of three atoms. It can be represented by the symbol O3, which stands for oxygen with three atoms attached to it. Trioxides are often used in chemistry and catalysis because they can provide strong oxidizing abilities. Trioxides are also known as oxides or oxide compounds. They include oxygen (O), nitrogen (N), and sulfur (S). These compounds have the formula O3, where the subscript 3 indicates that three atoms