Refer to the periodic table given in your book and now answer the following questions:
(a) Select the possible non metals that can show disproportionation reaction.
(b) Select three metals that can show disproportionation reaction.

Explanation

From the periodic table
The three metals that show disproportionation reactions are Cu, Ga and In. Their disproportionation reactions are as follows: `2Cu^(+) (aq) rarr Cu^(2+) (aq) + Cu(s)`
`3Ga^(+)(aq) rarr Ga^(3+) (aq) + 2Ga(s)`
`3In^(+) (aq) rarr In^(3+) (aq) + 2In (s)`
These metals can exist in three oxidation states, Cu: +2, 0, +1
Ga: +3, 0, +1
In: +3, 0, +1