20 mL of 0.1 M H₂SO₄ solution is added to 30 mL of of 0.2 M NH₄OH solution. The pH of the resultant mixture is : [pk_b of NH₄OH = 4.7].

Aluminium is usually found in +3 oxidation state. In contrast, thallium exists in + 1 and + 3 oxidation states. This is due to :

The highest value of the calculated spin only magnetic moment (in BM) among all the transition metal complexes is :

In general, the properties that decrease and increase down a group in the periodic table, respectively, are :