The maximum oxidation state shown by a p-block element is equal to the total number of valence electrons (i.e., the sum of the s and p-electrons).

Arsenic is a group 15 element and its atomic no. is 33.

N shows -3 in

Oxidation state of O is -2 and H is +1. Let the oxidation state of N is x.

(+1) +x + 3(-2) = 0

x = +5

N has maximum covalency of 4 since only four (one s and three p) orbitals are available for bonding. d orbitals are not available for bonding.

As we move down the group in periodic table , metallic character increases so Bi is a metal thus its oxide is basic.

In the solid and liquid states