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

Diborane reacts with ammonia under different conditions to give a variety of products. Which one among the following is not formed in these reactions?

Identify the correct statements:
$i$. Oxidation of $NaBH_4$ with $I_2$ gives $B_2H_6$
$ii$. $B_2H_6$ burns in oxygen and releases an enormous amount of energy
$iii$. $B_2H_6$ on hydrolysis gives a tribasic acid

Pick the correct statement.
$I$. Borax is a white crystalline solid containing $\left[B_4 O_5(OH)_4\right]^{2-}$ units.
$II$. The aqueous solution of borax is acidic in nature.
$III$. Cobalt gives a blue color in the borax bead test.

Which of the following statements is correct?

Which element of group $13$ does not show the group valency in its compounds?