When an excess of $NaOH$ solution is added to a solution of potassium alum,what do we obtain?

Draw the structure of boric acid showing hydrogen bonding. Which species is present in water? What is the hybridization of boron in this species?

The stability of $+1$ oxidation state among $Al$,$Ga$,$In$ and $Tl$ increases in the sequence:

Boric acid is polymeric due to

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

The correct orders among the following are
$A$. Atomic radius $: B < Al < Ga < In < Tl$
$B$. Electronegativity $: Al < Ga < In < Tl < B$
$C$. Density $: Tl < In < Ga < Al < B$
$D$. $1^{st}$ Ionisation Energy $: In < Al < Ga < Tl < B$
Choose the correct answer from the options given below $:$