Sodium percarbonate is an adduct* of sodium carbonate and hydrogen peroxide. It was first prepared in Russia in 1899. It is used an an oxidizing agent and is commonly seen in home and laundry cleaning products.
An adduct (from the Latin adductus, "drawn toward" alternatively, a contraction of "addition product") is a product of a direct addition of two or more distinct molecules, resulting in a single reaction product containing all atoms of all components.[