Describe and discuss the methods for deriving absolute geologic dates. How have these methods
influenced the Geologic Time Scale? Discuss possible sources of uncertainty in dates
determined using these methods. What will be an ideal response?
The student should discuss various radiometric dating systems, including radiocarbon dating,
uranium-lead, rubidium-strontium, samarium-neodymium, and potassium-argon. Especially
important is recognition of the fact that different half-lives for these systems allow them to date a
variety of events in the geologic record. Fission-track and tree-ring dating should also be
discussed. The student should also discuss effects of metamorphism on radiometric dating and
analytical uncertainties in chemical analyses.
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Describe how both the Sahara desert at (30 degrees north latitude) and the Amazon rain forest (along the equator) are both products of the same process driven by Hadley cells.
What would be an ideal response?
When surfaces such as twigs, leaves, and blades of grass cool below the saturation temperature, water vapor begins to condense upon them, forming tiny visible specks of water called ____________________. If the air temperature should drop to freezing or below, the ____________________ will freeze, becoming tiny beads of ice called ____________________
Fill in the blank with correct word.
It is possible for regional average temperatures to change by more than 5°C in less than a decade.
Answer the following statement true (T) or false (F)
Read carefully. Twice as much as one million trillion is two million trillion. One thousand times as much is 1000 million trillion. One million times as much is 1,000,000 million trillion, which is the same as one trillion trillion. Thus, one trillion trillion is a million times greater than a million trillion. Got that? So how many more water molecules than impurity molecules are there in a glass of water that is 99.9999% pure?
A. 1,000,000 (one million: 1 × 106) more water molecules than impurities molecules B. 1,000,000,000 (one billion: 1 × 109) more water molecules than impurities molecules C. 1,000,000,000,000,000,000 (one million trillion: 1 × 1018) more water molecules than impurities molecules D. 1000 (one thousand: 1 × 103) more water molecules than impurities molecules