The table below compares the radioactive decay rates of two materials. Material Original mass of material (in grams) Mass of material after 11,460 years (in grams) 1 100 25 2 200 25

Which statement about soil color is true? (2 points)

Which process of soil erosion is being prevented by the activity shown below? (2 points) © 2011 Polka Dot Images/Polka Dot/Thinkstock

The graph below shows the half life values of parent isotopes. Based on the graph, it can be concluded that the isotope which is most likely to be found with 12.5% of its original amount in 42 billion years is (2 points)

A soil sample is 35 percent sand, 10 percent clay, and 55 percent silt. Use the following soil texture triangle to determine the type of soil present in this sample. (2 points) Public Domain

The star named Polaris has a declination of approximately +90°. In what direction is Polaris located from the celestial equator? (4 points)

A star has right ascension of 5 hours. Which of these statements is correct about the star? (4 points)

The table below shows the right ascensions of two stars at a location. Name of star Right ascension (in hours) Star 1 1 Star 2 3 What is the interval between the times when the two stars cross the meridian at the location? (4 points)

Which of the following is the smallest single component of a typical soil? (2 points)

Which aspect of soil characteristics is a soil triangle used for? (2 points)