Identify the correct statements from the following : I. Ga ₂ O ₃ is an amphoteric oxide. II. The dimer of aluminium chloride has three Al - Cl - Al bridge bonds. III. Boron is very hard refractory solid of high melting temperature.

Step-by-step solution

(I) Ga ₂ O ₃ is an amphoteric oxide is the correct statement as it reacts with acid and base both, as shown below : Reaction with an acid Ga ₂ O ₃+6 HCl 2 GaCl ₃+3 H ₂ O Reaction with a base Ga ₂ O ₃+2 NaOH 2 NaGaO ₂+ H ₂ O (II) The dimer of aluminium chloride has three Al - Cl - Al bridge bond is not the correct statement as structure of Al ₂ Cl ₆ is as follows: (III) Boron is very hard refractory solid of high melting temperature is the correct statement as its melting point is 2349 ~K and is used as refractory s