Rubber consists of long chain molecules that form a network. This network with its entangled molecules is the secret behind the ability to stretch so much. Upon stretching the chain molecules are aligned until they are all straight resulting in an increase in the resistance to stretch. If you poke the stretched rubber it easily ruptures and pops. Where can you poke a balloon and be safe it doesn´t pop?

balloon[br]wooden skewer

1 Take an uninflated balloon and inflate it.[br][br]2 Take a sharp wooden skewer and poke it carefully into the balloon.[br][br]CAUTION: balloon will pop when you don't select the right spots to poke the skewer.[br][br]Where can you poke the skewer into the balloon without it popping? Can you also poke it completely through the whole ballloon to get a balloon on a skewer? Select the number(s) of the correct location(s).[br][br][br][br]