If IUPAC name of an element is "Unununnium" then the element belongs to $$n$$th group of periodic table. The value of $$n$$ is _______.

The IUPAC systematic naming convention for elements uses the following roots for digits:

0 = nil, 1 = un, 2 = bi, 3 = tri, 4 = quad, 5 = pent, 6 = hex, 7 = sept, 8 = oct, 9 = enn

The name "Unununnium" breaks down as:

$$\text{Un-un-un-ium} = 1\text{-}1\text{-}1 = \text{Element } 111$$

Element 111 is Roentgenium (Rg). To determine its group, we need to find its position in the periodic table.

Element 111 lies in the 7th period. The electron configuration follows the pattern:

$$[Rn]\, 5f^{14}\, 6d^{9}\, 7s^{2}$$

Wait — for element 111, we count from element 87 (Fr, Group 1):

87 (s-block, 2 elements) → 88, then 89-103 (f-block, 15 elements), then 104-111 (d-block).

In the d-block of period 7: element 104 is in Group 4, 105 in Group 5, ..., 111 is in Group $$4 + (111 - 104) = 4 + 7 = 11$$.

So element 111 belongs to Group 11 of the periodic table.

The answer is $$n = 11$$.