Mn2+ + BiO3 → MnO4 + Bi3+ I need the element oxidized, the element reduced and the full balanced equation

Write down the unbalanced equation ('skeleton equation') of the chemical reaction. All reactants and products must be known. For a better result write the reaction in ionic form.

Mn2+ + BiO3- + H+ → MnO4- + Bi3+

Step 2. Separate the process into half reactions. A redox reaction is nothing but both oxidation and reduction reactions taking place simultaneously.

a) Assign oxidation numbers for each atom in the equation. Oxidation number (also called oxidation state) is a measure of the degree of oxidation of an atom in a substance (see: Rules for assigning oxidation numbers).

it is stable as it is in group 0 which have full outer shells of electrons