During the process of differentiation,
1. the faster planets move farther out from
the Sun.
2. satellites separate from parent planets
and go into their own orbits.
3. the atmosphere of a planet changes from
oxidized to reduced.
4. the surface of a planet changes to resemble
Bayonne, New Jersey.
5. heavier materials sink to the centers of
molten planets.

Hydroelectricity provides about 7 percent of the electricity generated in the united states. (a) explain how a hydroelectric power plant converts energy stored in water into electricity. (b) identify two factors that determine the amount of electricity that can be generated by an individual hydroelectricity power plant. (c) describe the two main types of land-based hydroelectric power plants. (d) describe two economic advantages and two environmental disadvantages of hydroelectricity.