This holds a planet's atmosphere close to its surface:
A). Radiation
B). Gravity
C). Cloud cover
D). Moisture
E). Pressure
Gravity
Our atmosphere is a mixture of gases that surround Earth. It is kept in place by the pull of Earth's gravity. If Earth was a much smaller planet, like Mercury or Pluto, its gravity would be to weak to hold a large atmosphere.
2. Bears are usually hunted and killed for their
3. Soil erosion can be prevented by
4. Acid is an example of _____________
5. Which of the following is a nonrenewable energy resource?
6. In a pyramid of numbers, in a grassland ecosystem, the largest population is that of
7. Energy transformation through the food chain is
10. Charged particles from the sun that travel through space at high speeds are called: