White powder.
Sodium perborate is used in laundry detergents and bleaches. It releases more hydrogen peroxide than borax when it reacts with water. Hydrogen peroxide acts as a bleach, and this action is aided by the alkaline solution also produced by the reaction.
sodium perborate: InChI=1/BHO3.Na.H2O/c2-1-4-3;;/h3H;;1H2/q;+1;/p-1/fBO3.Na.H2O/h3h;;/q-1;m;
perborate: InChI=1/B2H4O8/c3-1(4)7-9-2(5,6)10-8-1/h3-6H/q-2