What is the most important reason why an icy moon is more likely to be geologically active than a rocky moon of the same size? What is the most important reason why an icy moon is more likely to be geologically active than a rocky moon of the same size? Ice contains more radioactive elements than rock. Ice is less rigid than rock. Ice is affected by tidal forces to a greater extent than rock. Ice is less dense than rock. Ice has a lower melting point than rock.