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

The element that has the least metallic character is ..........

Consider the following reactions.
$Na_{2}B_{4}O_{7} \xrightarrow{\Delta} 2 X + Y$
$CuSO_{4} + Y \xrightarrow{\text{Non-Luminous flame}} Z + SO_{3}$
$2Z + 2X + \text{Carbon} \xrightarrow{\text{Luminous flame}} 2Q + Na_{2}B_{4}O_{7} + CO$
The oxidation states of $Cu$ in $Z$ and $Q$, respectively are:

Select the correct statement about the hydrolysis of $BCl_3$ and $NCl_3$.

Which one of the following elements does not form triiodide on reacting with iodine?

The structure of diborane $(B_2H_6)$ contains