<span>The minerals that make up </span>rocks<span> have defined chemical </span>compositions<span> and rigid atomic structures. When sunlight strikes the </span>rock's<span> surface, the </span>composition<span> and atomic structure of the different minerals control the wavelengths they absorb or reflect.</span>
I would have to say it would have been the 30 because thats when the moon is closet to the earth so people would be able to see the eclipse better
Answer:
The mean center of population is the place where an imaginary, flat, weightless, and rigid map of the United States would balance perfectly if all residents were of equal weight. Historically, the movement of the center of population has reflected the expansion of the country, the settling of the frontier, waves of immigration and migration west and south. Since 1790, the center of population has moved steadily westward, angling to the southwest in recent decades.
SOURCE: Geography Division, "Centers of Population Computation for the United States 1950-2010," issued March 2011, available at www.census.gov/geo/www/2010census/centerpop2010/COP2010_documentation.pdf. Consulted for historical reference: Historical Atlas of the United States, National Geographic Society, 1988.
NOTE: The Proclamation Line of 1763 limited British settlement to areas east of the Appalachian Mountains. Alaska and Hawaii were not included in the calculation of the mean center of population until 1950. Puerto Rico was not included in any decade. For more information on the mean center of population, an animated map, and other resources. This graphic is adapted from the "Census Atlas of the United States" published by the Census Bureau in 2007.
Explanation:
D i am pretty sure that is the best answer plus alaska was into fur
The answer is steamboats! The first steamboat came year 1807 and was invented by John Fitch:)
