What is the Rock Cycle? Like most Earth materials, rocks are created and destroyed in cycles. The rock cycle is a model that describes the formation, breakdown, and reformation of a rock as a result of sedimentary, igneous, and metamorphic processes. All rocks are made up of minerals. A mineral is defined as a naturally occurring, crystalline solid of definite chemical composition and a characteristic crystal structure.
It isn't illegal to chew gum, but it is illegal to bring them into Singapore or sell them except for medical purposes. Since you can't buy gum (selling is illegal) there's no way to chew them so it's almost as good as not being able to chew gum. http://www.customs.gov.sg/leftNa...
To make things simple, gum is made up of rubber that is soft enough to chew, but has strong enough bonds to not dissolve in your mouth. It also has added sugar and flavor, so you'll actually chew it. Temperature ad environment are the main factors that affect gum elasticity. When you chew gum, the natural heat of your mouth and the surface of your teeth and tongue deform the gum, it becomes accustomed to that environment.