statement(I):  Bi+5 salts are very good oxidising agentsstatement(II):  Bismuth is more stable in +3 state than in +5 state

Due to Lanthanoid contraction , size increases from Sb to Bi is smallIn 'Bi' nuclear attraction over outermost electrons is more. Thus the paired 'ns' electrons are reluctantto uncouple and participate in bonding . Due to this reason 'Bi' shows an ox. state '+3' (corresponding to ground state)And it is unstable in higher ox. state(+5)Compounds of 'Bi' in '+5' state (except BiF5) are unstable and undergo reduction to form stable compounds with '+3' state