The number of water molecules present in borax,kernite and bauxite respectively are

Give the industrial preparation for diborane.

Which of the following statements is true about $H_3BO_3$?

In diborane,the $H-B-H$ bond angle is $120^o$. The hybridization of boron is likely to be

$A$ nonmetallic element of group $13$,used in making bulletproof vests,is an extremely hard solid of black colour. It can exist in many allotropic forms and has an unusually high melting point. Its trifluoride acts as a Lewis acid towards ammonia. The element exhibits a maximum covalence of four. Identify the element and write the reaction of its trifluoride with ammonia. Explain why the trifluoride acts as a Lewis acid.

Give important trends and anomalous properties of boron.