A) life has not changed significantly throughoutEarth’s historyB) life has evolved from complex to simple formsC) many organisms that lived on Earth have becomeextinctD) mammals developed early in the Precambrian timeperiod1. Based on fossil evidence, most scientists infer thatA) addition of free oxygen to Earth’s atmosphereB) formation of clastic sedimentary rocksC) movement of tectonic platesD) filling of the oceans by precipitation2. Which event in Earth’s history was dependent on thedevelopment of a certain type of life-form?
A) B)C) D)3. Which time line most accurately indicates when this sequence of events in earths history occurred?
4. The time line below represents the geologic history of Earth. Letters A, B, C, and D represent specific timesin Earth’s history.A) A B) B C) C D) DWhich letter best indicates when trilobites became extinct?A) B)C) D)5. Which bedrock drill core contains fossils of the life-formthat lived earliest in the Earths history?A) index fossils B) cementing agentC) texture D) color6. Which bedrock feature is most useful in correlatingsedimentary bedrock in one area with sedimentarybedrock in another area?A)B)C)D)7. Which pair of index fossils can be found in Ordovicianbedrock?
A) B)C) D)8. Which sequence of New York State index fossils shows the order in which the organisms appeared onEarth?9. Base your answer to the following question on the geologic cross section below. The cross section showsVermont index fossils in rock layers that have not been overturned. Rock unit A is an igneous intrusion andline XY represents an unconformity.Based on fossil evidence, determine the geologic period during which the unconformity formed.
10. Base your answer to the following question on the cross sections below, which show widely separatedoutcrops labeled I, II, and III. Index fossils are found in some of the rock layers in the three outcrops. Inoutcrop III, layers A, B, C, and D are labeled. Line XY represents an unconformity. Line GH represents afault.On outcrop II below, place the symbol ~~ for an unconformity between the two rock layers where theSilurian-age bedrock has been removed by erosion.
11. Base your answer to the following question on Thethree geologic columns below represent the rock layersin outcrops located several miles apart. The rock layershave not been overturned. Two different index fossilsare shown.A) B)C) D)Of the rock layers found in these three outcrops, whichlayer was probably formed most recently?A) carbon-14 B) potassium-40C) uranium-238 D) rubidium-8712. Which radioactive element would be best fordetermining the age of a 25,000-year-old rock samplecontaining organic remains?A) Carbon-14 has a relatively short half-life and toolittle carbon-14 is left after 50,000 years.B) Carbon-14 has a relatively long half-life and notenough carbon-14 has decayed after 50,000 years.C) Carbon-14 has been introduced as an impurity inmost materials older than 50,000 years.D) Carbon-14 has only existed on Earth during thelast 50,000 years.13. Why is carbon-14 not usually used to accurately dateobjects more than 50,000 years old?A) carbon-14 B) potassium-40C) rubidium-87 D) uranium-23814. Which radioactive substance has the longest half-life?
15. Base your answer to the following question on the diagram below, which represents a model of aradioactive sample with a half-life of 5000 years. The white boxes represent undecayed radioactivematerial and the shaded boxes represent the decayed material after the first half-life.A) carbon-14 B) potassium-40 C) uranium-238 D) rubidium-87Which radioactive isotope has a half-life closest in duration to this radioactive sample?A) 1,400 years B) 2,800 yearsC) 5,600 years D) 11,200 years16. A geologist uses carbon-14 to determine the age of asample of material found in a sedimentary deposit. Ifthe sample shows that 50 percent of the originalcarbon-14 is left, what is the approximate age of thesample?A) 1/8 g B) 1/16 gC) 1/32 g D) 1/64 g17. The table below gives information about the radioactivedecay of carbon-14. [Part of the table has been leftblank for student use.]What is the amount of the original carbon-14 remainingafter 34,200 years?A) 2,850 years B) 5,700 yearsC) 11,400 years D) 17,100 years18. A sample of wood that originally contained 100 gramsof carbon-14 now contains only 25 grams of carbon-14.Approximately how many years ago was this samplepart of a living tree?
A) 5,700 years B) 17,100 yearsC) 22,800 years D) 28,500 years19. How old is a fossil that has radioactively decayedthrough 4 half-lives of carbon-14?A) 2,800 years B) 5,700 yearsC) 11,400 years D) 17,100 years20. A sample of wood found in an ancient tomb contains25% of its original carbon-14. The age of this woodsample is approximately21. Base your answer to the following question on the diagram below, which represents a model of theradioactive decay of a particular element. The diagram shows the decay of a radioactive element into thestable decay element after one half-life period.If the radioactive element in this model is carbon-14, how much time will have passed after one half-life?A) B)C) D)22. Which graph best shows the radioactive decay ofcarbon-14?A) 0% B) 25% C) 50% D) 75%23. Radioactive carbon-14 dating has determined that afossil is 5.7 × 103 years old. What is the total amount ofthe original Cl4 still present in the fossil?A) 1,400 years B) 2,800 yearsC) 5,600 years D) 11,000 years24. An ancient bone was analyzed and found to containcarbon-14 that had decayed for nearly two half-lives.Approximately how old is the bone?
25. The diagram below shows the relative proportions ofcarbon-14 (C-14) to nitrogen-14 (N-14) in a rock.A) 2.85 × 103 B) 5.7 × 103C) 1.3 × 109 D) 4.5 × 109What is the most likely age of the rock?26. Base your answer to the following question on the date table below, which shows the radioactive decay ofcarbon-14. The number of years required to complete four half-lives has been left blank.How long does it take for radioactive carbon-14 to complete four half-lives?
27. The table below shows information about theradioactive decay of carbon-14.A) g B) g C) g D) gWhat is the amount of carbon-14 remaining after 28,500years?28. The table below gives information about the radioactivedecay of carbon-14. [Part of the table has been leftblank for student use.]A) g B) g C) g D) gWhat is the amount of the original carbon-14 remainingafter 34,200 years?