system
Given the following post, respond as if you're commenting on Reddit:
human
What's the difference between soft and hard rubber on the molecular level?
gpt
Hard, vlucanized rubber has molecular bonds that cross-link the long rubber polymers together, forming a rigid lattice; soft rubber doesn't have these cross links, so the rubber polymers can scrunch and stretch and slide past each other, making the substance softer and stretchier.