Explain borax bead test with a suitable example

Explanation

Borax Bead Test : This test is useful for the identification of coloured metal radicals in qualitative analysis. On heating, borax - swells into a white, opaque mass of anhydrous sodium tetraborate. When it is fused, borax glass.is obtained. This con tains sodium metaborate and `B_2O_3`. The boric anhydride com bines with metal oxides to form metal metaborates ás coloured beads. The reactions are as follows.
`Na_2B_4O_7.10H_2Orarr Na_2B_4O_7 overset("fused")(rarr)underset("Borax glass")(2NaBO_2+B_2O_3)`
`overset("Borax")(B_2O_3)+CoO rarr underset("Cobalt Metaborate (Blue, bead)")(Co(BO_2)_2)`