Cr + Ag(NO3) → Ag + Cr(NO3)
This is an oxidation-reduction (redox) reaction:
AgI + e- → Ag0 (reduction)
NV + 2 e- → NIII (reduction)
Cr0 - 3 e- → CrIII (oxidation)
Ag(NO3) is an oxidizing agent, Ag(NO3) is an oxidizing agent, Cr is a reducing agent.