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Final review
7th grade science; second semester review
49
Science
7th Grade
05/23/2011

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Cards

Term
Traces or remains of living things from long ago are
Definition
fossils
Term
Fossils that were common during a certain span of time and helped to determine the age of rocks and rock layers are
Definition
Index fossils
Term
The actual bodies or body parts or organisms are
Definition
original remains
Term
A tubular sample that shows layers of ice and snow built up over thousands of years is a(n)
Definition
Ice core
Term
The age of an object or event in relation to other objects or events is
Definition
Relative age
Term
The atual age of an event or object is
Definition
Absolute age
Term
The amount of time it takes a radioactive element to decay by 50% is called
Definition
Half Life
Term
James Hutton's theory that the same forces at work today were at work in the past was caled the theory of ______________
Definition
Uniformitarionism
Term
Earth's History divided into intervals of time defined by major events or changes on Earth is
Definition
Geological time scale
Term
Fossils can only form when
Definition
Conditions are right
Term
What are the three substances that can preserve original remains
Definition
Ice, Tar, and Amber
Term
What are the earliest known fossils found on Earth
Definition
One celled organisms
Term
What type of rock are fossils most commonly found in
Definition
Sedimentary
Term
Why are fossils not found in igneous rock
Definition
It's to hot. The fossils would melt
Term
Scientists study sedimentary rock to determine
Definition
The age of fossils
Term
Define the difference between relative age and absolute age
Definition

Relative age is estimated

 

Absolute age is the actual age

Term
What can scientis determine by studying tree rings
Definition
How old the tree is; Weather patterns
Term
What can scientists determine by studying ice cores
Definition
The weather over time
Term
The powder left behind when a mineral is scraped across a porcelain tile is
Definition
Streak
Term
What do scientists use to determine hardness
Definition
The Mohs Hardness scale
Term
The way in which light reflects from a mineral's surface is it's 
Definition
Luster 
Term
The tendency of a mineral to break along flat surfaces is called
Definition
Clevage
Term
The tendency of a mineral to break into irregular pieces is called
Definition
Fracture
Term
The amount of mass in a given volume of a substance
Definition
Density
Term
A minerals resistance to being scratched is its 
Definition
Hardness
Term
Molten rock inside the Earth is called
Definition
Magma
Term
Molten rock that reaches Earths surface is called
Definition
Lava
Term
Rock that contains enough of a mineral to be mined for a profit is
Definition
Ore
Term
What are 2 types of mining
Definition
Deep and Surface
Term
What are the 4 characteristics of a mineral
Definition
Solid, Made in Nature, Crystal structure, and definate chemical makeup
Term
In what layer of Earth are all rock-forming minerals
Definition
Crust
Term
What is the most common group of minerals
Definition
Silicates
Term
What is a naturally formed solid that is usually made up of one or more minerals
Definition
Rock
Term
What is the process that forms changes and breaks down rock
Definition
Rock Cycle
Term
What forms when molten rock cools and becomes a solid
Definition
Igneous Rock
Term
What forms when pieces of older rocks, plants, and other loose materials get pressed or cemented together
Definition
Sedimentary rock
Term
What forms when heat or pressure causes older rocks to change into new types of rock
Definition
Metamorphic rock
Term
What are materials that settle out of water or air.
Definition
Sediments
Term
What is the process in which an exsisting rock is changed by heat or pressure
Definition
metamorphism
Term
What is the process in which atoms join together differently as new bonds form
Definition
Recrystalization
Term
What is an arrangement of minerals in a flat, wavy, or parallel bands
Definition
Foliation
Term
Explain the difference between an intrusive and extrusive igneous rock
Definition

Intrusive- forms from magma

Extrusive- forms from lava

Term
Where does the rock cycle begin and end
Definition
No where
Term
Why do some igneous rocks have large crystals and some have small
Definition
Not enough space. Large crystals have a little time to cool, where as Smaller crystals have a longer time. 
Term
What sedimentary rock forms from the remains of ancient plants that have been buried and pressed together
Definition
Coal
Term
What sedimentary rock forms in caves due to evaporate and when sea shells are cemented together.
Definition
Limestone
Term
What mineral is formed in the shels and skeletons of ocean organisms
Definition
Calcite
Term
What is the most common of rock no Earth's surface. 
Definition
Sedimentary rock
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