Question

1. is the following sentence true or false? fossils can form when the remains of an organism decay. 8. circle the letter of each sentence that is true about molds and casts. a. both molds and casts copy the shape of ancient organisms. b. a mold forms when the hard part of an organism is buried in sediment. c. a cast is a hollow area in sediment in the shape of an organism. d. molds and casts do not show details of the organisms structure. 9. fossils in which minerals replace all or part of an organism are called fossils. 10. is the following sentence true or false? petrified fossils can form when the minerals in water make a copy of the organism. 11. what is a carbon film?

Explanation:

1. Fossils form from the remains of decayed organisms, so the statement is true.
2. A mold forms when the hard part of an organism is buried in sediment and then decays, leaving an impression. A cast is a copy of the shape of the organism that fills the mold. So both a and b are correct facts about molds and casts.
3. When minerals replace all or part of an organism, they are called petrified fossils, which is a correct definition.
4. Petrified fossils form when minerals in water gradually replace the organic material of an organism to make a copy of it, so the statement is true.
5. A carbon - film fossil is a thin film of carbon residue that forms when an organism is compressed and the volatile elements are driven off, leaving behind a carbon - rich residue that preserves the shape of the organism.

Answer:

1. True
2. a. Both molds and casts copy the shape of ancient organisms; b. A mold forms when the hard part of an organism is buried in sediment.
3. Petrified fossils
4. True
5. A thin film of carbon residue that preserves the shape of an organism formed when the organism is compressed and volatile elements are driven off.