How do scientists believe that Earth most likely formed?
|A)||from a star that cooled|
|B)||from the collapse of a solar nebula|
|C)||from the collision of two other planets|
|D)||from a piece of the Sun that broke away|
|E)||from an exploding star|
What was the source of the water that formed the oceans on Earth?
|B)||underground bodies of water|
|E)||water vapor from volcanic eruptions and ice from comets|
Which phrase best describes the visible surface of Earth?
|A)||50 percent water and 50 percent land|
|B)||about 70 percent water and 30 percent land|
|C)||about 70 percent land and 30 percent water|
|D)||about 90 percent land and 10 percent water|
|E)||about 90 percent water and 10 percent land|
Which of the following statements best describes a geochemical cycle?
|A)||A geochemical cycle is the movement of elements from one chemical storehouse to another.|
|B)||A geochemical cycle is the periodic occurrence of an ice age.|
|C)||A geochemical cycle is the slow change in adaptation that organisms show over time.|
|D)||A geochemical cycle refers to the seasonal changes of weather.|
|E)||A geochemical cycle refers to the solar heating of Earth.|
Which of the following is the best definition of plate tectonics?
|A)||Earth's core is hot, molten rock and is the source of heat that leads to volcanic eruptions.|
|B)||The land below Earth's oceans is flat and does not have underwater mountains and valleys similar to mountains found on the continents.|
|C)||Earth's surface (crust) is made up of several large sections of land (plates) that slowly move around on the mantle, changing the position of continents as they move.|
|D)||Earth's continents will someday be grouped together as a single, large landmass.|
|E)||Earth is about 4.6 billion years old.|
What role does ozone play in making life possible on Earth?
|A)||Ozone is an atmospheric gas that humans and other organisms breathe, thus making life possible on Earth.|
|B)||Ozone forms a blanket of atmospheric gas that surrounds Earth and helps keep Earth warm, preventing the occurrence of ice ages.|
|C)||Ozone is a protective layer of atmospheric gas that protects Earth from the impact of large asteroids.|
|D)||Ozone is an atmospheric gas that absorbs much of the dangerous, high-energy ultraviolet sunlight that otherwise would reach Earth's surface.|
|E)||Ozone gas is the gas used by plants during the process of photosynthesis, making the production of food possible.|
What feature of Earth is responsible for the four seasons (summer, fall, winter, and spring)?
|A)||the tilt in Earth's rotation axis|
|B)||the fact that Earth's surface is mainly water|
|C)||the distance of Earth from the Sun|
|D)||the movement of the Moon around Earth|
|E)||the fact that summer months are generally much warmer than winter months|
What does a weather reporter mean by the statement, "The humidity level is 50 percent."
|A)||The air temperature is halfway between freezing and boiling.|
|B)||There is a 50 percent chance of rain today.|
|C)||Air pressure (barometric pressure) is rising.|
|D)||The air currently contains 50 percent of the water vapor that it can hold.|
|E)||There is an equal amount of blue sky and cloud cover.|
How is weathering different from erosion?
|A)||Weathering occurs only during winter months; erosion occurs only during summer months.|
|B)||Weathering is the movement of rock fragments; erosion is the breaking down of rocks into smaller pieces.|
|C)||Weathering is the breaking down of rock into smaller pieces; erosion is the movement of rock fragments.|
|D)||Weathering is a breaking down of rock, while erosion is a combining of smaller rocks to make larger rocks.|
|E)||Erosion occurs before weathering.|
What information can scientists gain from the study of fossils?
|A)||Fossils give clues about what causes seasons on Earth.|
|B)||Fossils give clues about how Earth formed.|
|C)||Fossils give clues about the exact age of Earth.|
|D)||Fossils help scientists predict weather on a day-to-day basis.|
|E)||Fossils give clues about extinct forms of life and about the aging process of Earth itself.|