If a rock started with 1,000 atoms of a parent but now contains 250 atoms, how many half lives have passed?

A. 2 half lives
B. .5 half lives
C. .25 half lives
D. 4 half lives
E. There is no way to tell.


Answer: A

Environmental & Atmospheric Sciences

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Which of the following is commonly associated with tributaries?

A) Rapids when the tributary joins the main river B) Delivery of sediment to the main river C) An increase in the discharge in the main river D) All of these are correct.

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The goal of a deposit-refund program is to

A. inform consumers of the market choices. B. give companies the right to emit specified quantities of pollutants. C. encourage product recycling through the refund of a deposit. D. use tax money to fund environmental cleanup programs.

Environmental & Atmospheric Sciences

Suffering the impact of swarms of locusts, a farmer uses an airplane to spray a malathion, a neurotoxic agent, over 1,500 acres of his corn field. This farmer is trying to address this pest problem by using

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Environmental & Atmospheric Sciences

Compared to the “boundary course,” why would the present course of the Mississippi River be an advantage to river traffic such as barges?

The following questions are based on Map T-5, a portion of the “Jackson, Mississippi-Louisiana” topographic map (scale 1:250,000; contour interval 50 feet; dashed lines are supplementary contours at 25-foot intervals). This map shows the Mississippi River near the town of Vicksburg, Mississippi (32°49'56"N, 91°11'07"W). A color satellite image of this same region is shown in Figure 40-5 (scan the QR code for this exercise or go to the Lab Manual website and Exercise 40). The eastern bluffs of the Mississippi River floodplain can be seen in the southeast corner of the map. The dashed black line along the Mississippi River shows the state boundary between Mississippi and Louisiana. Notice that the “boundary course” of the Mississippi River is quite different from the present course of the river. Some of the changes were natural, others were artificial. There is an extensive set of artificial levees along the course of the river (shown with closely spaced brown tick marks). What will be an ideal response?

Environmental & Atmospheric Sciences