During the borax bead test, heating borax yields a transparent glassy bead. When a copper salt is he — p Block Elements Chemistry Question

💡 Solution & Explanation

Heating borax yields a glassy bead consisting of sodium metaborate ($NaBO_2$) and boric anhydride ($B_2O_3$). The basic copper oxide reacts with acidic $B_2O_3$ to form Copper(II) metaborate, $Cu(BO_2)_2$, which is blue.