sentences: in the rock cycle, old rocks are physically changed to form new rocks & in the rock cycle, new rocks are formed from broken down rock ->  in the rock cycle, new rocks are made from old rocks physically changing  in the rock cycle, new rocks are made from old rocks physically changing & if something is physically changed then the mass of that something will stay the same ->  as the class of a rock changes , the mass of the rock will stay the same  mass means the amount of matter that makes up an object & matter is a kind of material ->  mass means the amount of material that makes up an object  as the class of a rock changes , the mass of the rock will stay the same & mass means the amount of material that makes up an object ->  as the class of a rock changes, the amount of material that makes up that rock will stay the same  as the class of a rock changes, the amount of material that makes up that rock will stay the same & the class of a rock changing is a kind of earth process ->  as earth processes change, the amount of material that makes up rocks will stay the same  as earth processes change, the amount of material that makes up rocks will stay the same & earth is made of rock -> as the earth processes change , the total amount of material on earth will stay the same