Which element in group 15 is the strongest metallic character?

Bismuth (Bi)

Explanation:

Elements of the group 15 are nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb) and bismuth (Bi).

In the periodic table, metallic character increases down the group.

On the basis of metallic character, group 15 elements are arranged in the ascending order as follows:

N < P < As < Sb < Bi

Nitrogen and phosphorous are non-metal.

Arsenic and bismuth are metalloid.

Being last in the group, Bi is a metal and hence has strongest metallic character.