During the borax bead test with CuSO4, a blue green colour of the bead was observed in Oxidizing flame due to the formation of

The blue-green color observed in the borax bead test with CuSO₄ in an oxidizing flame is due to the formation of Cu(BO₂)₂.

Explanation:

During the test, borax reacts with copper ions (Cu²⁺) to form copper metaborate (Cu(BO₂)₂) in the oxidizing flame, which gives the characteristic blue-green color. This happens as the oxidizing flame provides sufficient oxygen to form the metaborate.

Correct Answer: Cu(BO₂)₂.