5b Feel the Heat
Background
Rubber consists of long chain molecules that form a network. In its relaxed form a rubber band is in a highly disordered internal state. Upon stretching the long chain molecules of the rubber band are aligned and the disorder decreases. What do you feel if you stretch a rubber band fast and bring it to your lips?

What you need:
thick rubber band or rubber balloon
What do you have to do?
1 Take a thick rubberband or even better a balloon.
2 Stretch it fast by pulling both ends apart and immediately touch it to your lips.
What do you feel? Does the rubber band feel (1) hot/warmer/ (2) colder/cooler? Type the number of the correct answer into the box below.