Ch. 3 Key Terms

Question 1

Geosphere

Answer 1

The solid part of the Earth that consists of all rock, as well as the soils and loose rocks on Earth’s surface.

Question 2

Hydrosphere

Answer 2

Makes up all of the water on or near Earth’s surface.

Question 3

Crust

Answer 3

The thin layer of Earth composed almost entirely of light elements. The crust makes up less than 1 percent of the Earth’s mass.

Question 4

Mantle

Answer 4

The layer beneath the crust that makes up 68 percent of the Earth’s mass. The mantle is approximately 2,900 km thick and is made up of rocks of medium density.

Question 5

Core

Answer 5

The innermost layer of the Earth. The radius of the core s approximately 3,400 km and is composed of elements with the greatest density.

Question 6

Lithosphere

Answer 6

The outermost layer of the Earth. A cool rigid layer that is 15 km to 300 km thick. That includes the crust and upper part of the mantle.

Question 7

Asthenosphere

Answer 7

The layer beneath the lithosphere. A solid layer of the mantle that is made of rock that flows very slowly and allowed tectonic plates to move above it.

Question 8

Tectonic Plate

Answer 8

The lithosphere is made up of tectonic plates that glide across the asthenosphere. The continents are located on these tectonic plates.

Question 9

Chemical Weathering

Answer 9

Wears down rocks, making them smoother over time.

Question 10

Erosion

Answer 10

Transports the materials of weathered rocks elsewhere.

Question 11

Atmosphere

Answer 11

The mixture of gasses that surround Earth. Nitrogen, oxygen, carbon dioxide, and other gasses are a part of this mixture.

Question 12

Troposphere

Answer 12

The atmospheric layer nearest to Earth,s surface. Extends to about 18 km above Earth’s surface. Almost all the weather occurs in this area.

Question 13

Stratosphere

Answer 13

The area above the troposphere. Extends from 18 km to about 50 km above the Earth.

Question 14

Ozone

Answer 14

The Ozone layer within the stratosphere limits the amount of harmful UV rays that reach Earth.

Question 15

Radiation

Answer 15

The transfer of energy by electromagnetic waves. When you stand in front of a fire, the warmth you feel is being transmitted by radiation.

Question 16

Conduction

Answer 16

The transfer of energy in the form of heat by direct physical contact.

Question 17

Convection

Answer 17

The transfer of energy that takes place when variations in temperature move the matter making up air.

Question 18

Greenhouse Effect

Answer 18

The process in which greenhouse gases absorb and reradiate infrared radiation near the Earth. Without this, the Earth would be too cold to sustain life.

Question 19

Water Cycle

Answer 19

The continuous movement of water into the air, onto land, and then back to water sources.

Question 20

Evaporation

Answer 20

The process by which liquid water is heated by the sun and then rises into the atmosphere as water vapor.

Question 21

Condensation

Answer 21

Water vapor forms water droplets on dust particles. These water droplets form clouds, in which the water droplets collide, stick together and create heavier larger droplets. These droplets fall from clouds as rain.

Question 22

Precipitation

Answer 22

Water droplets falling from the sky. May also take the form of snow, sleet, or hail.

Question 23

Salinity

Answer 23

The concentration of all the dissolved salts on the ocean.

Question 24

Fresh Water

Answer 24

Most of the Earth’s water is saltwater but a little more than 3 percent of it is freshwater meaning that there is no salt in the water. Most of the freshwater in the world is locked up in polar ice caps and glaciers.

Question 25

Biosphere

Answer 25

The narrow layer around the Earth’s surface that life can live and exist in. The biosphere extends about 12 km into the ocean and about 9 km into the atmosphere.