Unit 7 Test ReviewMs Grant

Trace fossils are much more common than body fossils. Which of the following best explains why trace fossils are more common?

A. Trace fossils take less time to form.

B. Body fossils require soft sediment to form.

C. An organism is more likely to live on soft sediment where trace fossils form.

D. A single animal can leave thousands of traces in its lifetime but will leave only one body when it dies.

D. A single animal can leave thousands of traces in its lifetime but will only leave one body when it dies

AND THE ANSWER IS……………

What materials does radiometric dating use to determine the age of objects?

A. fossilsB. isotopesC. tree ringsD. rock layers

B. isotopes

AND THE ANSWER IS……………

An igneous intrusion cuts through three layers of sedimentary rock. Which rock is the youngest?

A. the igneous intrusionB. the top layer of sedimentary rockC. the middle layer of sedimentary rockD. the bottom layer of sedimentary rock

A. the igneous intrusion

AND THE ANSWER IS……………

What is the law of superposition?

A. Igneous rock is older than nearby sedimentary rock, which is older than nearby metamorphic rock.

B. A sedimentary rock layer in its original position is older than the layers above it and younger than the layers below it.

C. Metamorphic rock is older than nearby sedimentary rock because sedimentary rock is deposited before metamorphic rock forms.

D.The exact age of a sedimentary rock layer can be found using the layers above and below it, even if the layers are not in their original positions.

B. A sedimentary rock layer in its original position is older than the layers above it and younger than the layers below it.

AND THE ANSWER IS……………

Earth’s surface features slowly change over time. For example, sharp, jagged mountain ranges become lower and more rounded over time. What factor/s is responsible for this change in their shape?

A. weathering and erosionB. depositionC. movement of continentsD. collisions between continental plates

A. weathering and erosion

AND THE ANSWER IS……………

Chase wants to determine a more accurate age of a shell that is known to be between 10,000 and 30,000 years old. Which method would be most useful for finding a more precise age of the shell?

 A. radiocarbon datingB. uranium-lead datingC. potassium-argon datingD. relative dating

A. radiocarbon dating

AND THE ANSWER IS……………

Radiocarbon dating has a shorter useful time range than potassium-argon dating. Which statement best explains why?

A. Carbon-14 is a common component of living things.

B. Carbon-14 is not a common component of minerals.

C. Carbon-14 has a longer half-life than potassium-40.

D. Carbon-14 has a shorter half-life than potassium-40.  

D. Carbon-14 has a shorter half-life than potassium-40

AND THE ANSWER IS……………

Each radiometric dating method is useful for a specific time range. Which method has the most useful time range of 100,000 to a few billion years old?

A. relative datingB. radiocarbon datingC. uranium-lead datingD. potassium-argon dating

D. potassium-argon dating

AND THE ANSWER IS……………

A geologist is studying three layers of sedimentary rock in an area. The layers have not shifted from their original positions. The geologist records the relative ages of the rocks. The bottom layer is listed as the oldest. The top layer is listed as the youngest. What did the geologist use to determine the relative ages of the rocks?

A. mineral contentB. radioactive decayC. the law of superpositionD. the principle of unconformity

C. the law of superposition

AND THE ANSWER IS……………

Which of the following methods is most likely to be used to determine the absolute age of animal bones that are less than 45,000 years old?

A. radiocarbon datingB. potassium-argon datingC. uranium-lead datingD. relative dating

A. radiocarbon dating

AND THE ANSWER IS……………

Jun makes a poster to explain how the law of superposition applies to rock layers. He explained the ages of the top three layers. He still needs to explain the age of layer 1. His diagram is shown below.

How should he explain the age of layer 1?

A. It is the youngest layer because it is protected by the other layers.B. It is the oldest layer because it was deposited before the other layers.C. It is older than layer 2 because it is thicker and has been worn away the least.D. It is three times younger than layer 4 because it is three layers below layer 4.

B. It is the oldest layer because it was deposited before the other layers.

AND THE ANSWER IS……………

Layers of rock are not always found in uniform layers. They may be cut by faults. Melted rock may be pushed into the layers, where it becomes solid. The diagram shows rock layers that are cut by a fault and two bodies of rock (rock 1 and rock 2).

What are the relative ages of the features in order of oldest to youngest?A. fault, rock 1, rock 2, layer 1B. layer 1, rock 2, rock 1, faultC. rock 2, layer 1, rock 1, faultD. fault, rock 2, layer 1, rock 1

B. layer 1, rock 2, rock 1, fault

AND THE ANSWER IS……………

The diagram below shows one kind of radioactive decay that is used for dating.

Which statement best describes what information is needed to determine the age of a rock sample using this type of dating method?A. the exact mass of uranium-238 in the sampleB. the amount of lead-206 present in the sampleC. the energy being released by the uranium-238D. the relative amounts of uranium-238 and lead-206

D. the relative amounts of uranium-238 and lead-206

AND THE ANSWER IS……………

During most of Florida’s geologic history, the state was covered by the ocean. Today, the land surface of Florida is covered mostly by sediment and sedimentary rock. If you were to analyze the composition of Florida’s sedimentary rocks, which type of fossil would you least likely find?

A. fossils of seashellsB. fossils of fish bonesC. fossils of palm frondsD. fossils of marine organisms

C. fossils of palm fronds

AND THE ANSWER IS……………

Scientists from three parts of Florida are comparing the rock layers in their areas. They want to arrange the layers according to their relative ages. The diagram shows the rock layers from each area.

Which area has the youngest top layer compared to the other areas?A. area 1 C. area 3B. area 2 D. The ages of the top layers are all the same.

A. area 1

AND THE ANSWER IS……………

Scientists have discovered dinosaur fossils that have evidence of feathers. Some scientists think the feathers might have kept the dinosaurs warm. If so, in what type of environment did these dinosaurs probably live?

A. hot desertB. tropical rain forestC. region near the equatorD. area with cold seasonal temperatures

D. area with cold seasonal temperatures

AND THE ANSWER IS……………

To determine when a volcano erupted, Michael used a sample of a mineral that formed when the lava cooled and became solid rock. He measured the amount of argon-40 in the sample to find how much potassium-40 had decayed since the rock formed. What else would Michael need to know to find the age of the mineral in years?

A. the half-life of potassium-40B. the amount of energy releasedC. the mass of a potassium-40 atomD. the time it takes argon-40 to decay

A. the half-life of potassium-40

AND THE ANSWER IS……………

GOOD LUCK!!!