How can mountain formation be described according to the theory of plate tonics

Convergent plates slowly come together, and over an amount of time, push together, and one either submerges, or they both buckle. Either way can form a mountain, because either way raises land up to the point where it eventually forms mountains.

Aphysical change is one that you can put in and remove like a ham sandwich. the stuff you put in there can be changem its not permanet. a chemical change is on that can't be change thats permanet. like when you make a cake and bake it. you can't get those ingredients back.

Ido not understand.