The acidic character of the group- 15 elements in the increasing order is

Step-by-step solution

Nitrogen, phosphorus, arsenic, antimony and bismuth are elements of group 15. Acidic character of oxides of this group decreases and basicity increases down the group. On moving down the group, the atomic size increases, electronegativity decreases and metallic character increases. i.e. Bi ₂ O ₃ < Sb ₂ O ₃ < As ₂ O ₃ < P ₂ O ₃ .