1. This occurs because of the unusual polymer structure of rubber. When the long chains get hotter and vibrate, they actually shorten, causing the material to contract. When the chains cool down, they relax and stretch out, causing the material to expand.
2. glass, ceramic, graphite
3. They are brittle that's why you can't stretch it.
Answers & Comments
Answers:
1. This occurs because of the unusual polymer structure of rubber. When the long chains get hotter and vibrate, they actually shorten, causing the material to contract. When the chains cool down, they relax and stretch out, causing the material to expand.
2. glass, ceramic, graphite
3. They are brittle that's why you can't stretch it.