8Th Grade Science Facts

Front 1

#78 The ____________ ________ is the elevated point at which the flowing water on a continent goes in one direction or another.

Back 1

Continental Divide

Front 2

#81 ____________ _______ are groups of mountain ranges that can cover thousands of miles.

Back 2

Mountain Chains

Front 3

#89 ___________ are non-living, naturally occurring compouds in the Earth.

Back 3

Minerals

Front 4

#90 ___________ is the process in which all kinds of rocks are broken down into smaller pieces over time

Back 4

Weathering

Front 5

#91 ____________ ___________ occurs when rocks break apart due to ice, temerature, or gravity. These result in rocks being broken into smaller pieces.

Back 5

Mechanical Weathering

Front 6

#92 ___________ ____________ occurs when plants or animals (water, acids, oxygen) change the rocks into new substances, causing the rock to break down into smaller pieces.

Back 6

Chemical Weathering

Front 7

#95 ____________ occurs when the rock pieces carried by erosion are dropped off somewhere else: a deposit of rock. Common areas for deposition are lake bottoms, ocean floor, deltas, beaches, swamps.

Back 7

Deposition

Front 8

#97 _______ is the decaying plant and animal matter that creates the dark-colored material in soils. It is very important for plant growth.

Back 8

Humus

Front 9

#100 When studying different layers of rock, the rock layer on the bottom is usually the oldest layer; the top layer is usually the most recent. This is called __________ ________.

Back 9

Relative Dating

Front 10

#108 Becides ________, _______, and ______ ______ keep the Great Lakes from drying up.

Back 10

Rainfall; Runoff; Snow Melt

Front 11

#110 Our largest source of fresh water comes from ____________.

Back 11

Groundwater

Front 12

#115 Chemicals in water are naturally __________ by the soil.

Back 12

Filtered

Front 13

#117 The main sources of _______ __________ are sewage, house-hold dumping, industrial wastes an agriculture run-off.

Back 13

Water Pollution

Front 14

#121 The sun is a star. Stars make their own light through nuclear reactions. This is called ________ ______

Back 14

Emitted Light

Front 15

#135 The ______ ________ are new moon, cresent moon, quarter moon, gibbous moon, and full moon.

Back 15

Moon Phases

Front 16

#136 A _______ ________ occurs when the moon moves in front of the sun during the day, creating a shadow and blocking sunlight from part of the earth.

Back 16

Solar Eclipse

Front 17

#137 A ______ ________ occurs when the earth blocks the sun's light, creating a shadow on the moon at night.

Back 17

Lunar Eclipse

Front 18

#141 The ____________ of a planet affects how much ______ it can hold. Too much or too little heat can prevent life from surviving. Our atmosphere has a layer that ________ ___ from the sun's dangerous _____: the ozone. Without itm we could not survive.

Back 18

Atmosphere; Heat; Protect Us; Rays

Front 19

#143 In the solar system, the ______, _______ planets (Jupiter, Saturn, Uranus, Neptune) do not have a solid surface. They are planets made of _______.

Back 19

Large; Outer; Gases

Front 20

#144 In our solar system, the ________, ______ planets (Mercury, Venus, Earth, Mars, and Pluto) have ______ rock surfaces.

Back 20

Smaller; Inner; Solid