Review Notes – Semester One – Earth Science -
When a conclusion is based on facts that have not been directly observed you are inferring.
The liquid area that surrounds the Earth’s center is the outer core.
Earthquakes and volcanoes occur most frequently at the boundaries of two plates.
A mineral that contains something useful and can be sold is an ore.
The solid area of the Earth’s core is the inner core.
The cycle of movement of material thatheat rises, cool, sinks are convection currents.
You form a hypothesis before you conduct an experiment
The science skill that means explaining why something happened is concluding.
Rocks are made up of two or more different minerals
The area below the surface of the Earth where the Earthquake begins is the focus.
The area of the surface locateddirectly above the focus is called the epicenter.
Each time you complete an experiment it is called a trial.
Mountains can form when plates collide.(fault)
A procedure designed to test a hypothesis is called an experiment
A rock that is melted and cools formsigneous rock.
Getting a clear idea of the problem isthe first step in the scientific method.
A naturally occurring inorganic solid with a definite structure composition is a mineral..
A large section of the Earth’s crust and upper mantle is the lithosphere.
A large section of the Earth’s crust and upper mantleis broken up into seven major pieces called plates.
You draw a conclusion at the end of an experiment.
Rocks exposed to the elements becomeweathered; the weatheredbits formsedimentary rock.
The model that shows how rocks recycled from one type to another is called the rock cycle.
The top layer of the Earth is called the crust.
The size of mineral crystals depends on how long it takes for the mineral to cool.
There are so many earthquakes in Californiabecause there are many faultsthere.
The thickest layer of the Earth is the mantle.
Metamorphic rocks form when rocks are changed by heat and pressure.
Extrusive igneous rocks form outside the Earth’s crust.
The seafloor spreads because magma flows into the gap in the mid ocean ridges.
The exact spot an earthquake occurs is called the focus.
Solids that have repeating patterns of atoms are called crystals.
The shaking of the Earth produced by a fast release of energy is called an earthquake.
Cleavage, hardness, color, luster, fracture, specific gravity, streak are all properties to identify minerals.
A place where hot magma breaks through to the surface of the Earth is called a volcano.
Most earthquakes and volcanoes occur near the Ring of Fire.
Observing is a science skill that means to examine something very carefully.
Factors in an experiment that can change are called variables.
The more trials run in an experiment, the more information you have to base your conclusions on, thus making the probability your conclusion is correct greater.
Intrusive igneous rocks form inside the Earth.
Atoms are the smallest part of an element that has all the properties of that element.
Elements are the basic building blocks of all matter.
Elements are substances that are made up of a single type of atom.
A mineral is an inorganic (nonliving) material, with a definite chemical composition and atomic structure.
A property is a characteristic of a mineral.
Properties help scientists identify minerals.
The six main properties used to identify minerals are color, luster, streak, hardness, specific gravity, and cleavage/fracture.
A better determinant of the true color of a mineral is its streak.
Streak is used to see the color of the mineral under the top layer or coating on the mineral.
The color of the streak is always the same, whether or not the mineral has impurities. For example, quartz leaves a white streak, whether it's violet (amethyst), pink (rose quartz), or brown (smoky quartz).
Luster is the way the surface of a mineral reflects light. Luster should be observed on a cut or freshly broken, untarnished surface.
There are two general types of luster -- metallic and non-metallic.
Mohs scale of hardness is used to determine the approximate hardness of minerals. The minerals on the scale are arranged from softest (Talc) to hardest (Diamond).
When a mineral splits or cracks along a parallel or a flat plane, this splitting is called cleavage
Fracture – When a mineral breaks at random lines instead of at consistent flat plane.
Specific gravity is basically the density of a mineral.
Rocks differ from minerals because rocks are made of two or more different minerals that have been:
Cemented together, or
Changed by heat and pressure, or
Melted and cooled together.
Rocks are classified by the way they were formed
The three main rock classifications are: Igneous, Metamorphic, and Sedimentary
There are two main types of igneous rocks
Intrusive – Igneous rocks that formed inside the Earth.
Extrusive – Igneous rocks that cooled on the Earth’s surface
Crystals that cool intrusively are larger than extrusive crystals; because they cool slower, giving those more time to grow.
Metamorphosis means change (think caterpillar to butterfly). Rocks that are changed into a new type of rock due to heat and pressure deep in the Earth are called metamorphic rocks.
There are two main types of metamorphic rocks:
Foliated – Metamorphic rocks in which the minerals have been flattened and pushed down into parallel layers. The bands in foliated metamorphic rock look like pages in a book.
Non-Foliated - Metamorphic rocks that do not display layers.
Rocks that are formed from the cementing together of small pieces of rocks, minerals or shells (Sediments) are called sedimentary rocks.
Compaction occurs in sedimentary rocks when the weight of top layers press down on the lower layers .
Cementation occurs in sedimentary rocks when water with dissolved minerals goes through the sediments and “glues” the sediments together.
If any rock, sedimentary, metamorphic, or igneous becomes exposed it will start to become weathered. The weathered bits (sediments) eventually are deposited and form sedimentary rock.
If any rock, sedimentary, metamorphic, or igneous comes in contact with intense heat and pressure it will change and become a metamorphic rock.
If any rock, sedimentary, metamorphic, or igneous, melts, (becomes magma), cools and hardens, it has become an igneous rock.
Clay in soil will not let water pass through it; while sand and gravel let water to easily pass through.
Sand and gravelhave large spaces between the particles which allow more water to be stored compared to other types of soils.
Humus (dead & decaying material) is the source in soil of good nutrients for plants.
Chemical weathering is where the parent rock is chemically changed (green on copper)
Mechanical weathering is the breakdown of material by physical disintegration, only the size of the changes.
Weathering is the breakdown of rock into smaller pieces; having the same mineral as the parent rock
Agents of chemical weathering are rainwater, oxygen, carbon dioxide, and plant/animal decay acids.
Erosion is the process of moving the weathered sediments (wind or water)
Deposition is the process where the eroded sediments are deposited or dropped into a new location.
Soil is loose, weathered rock and organic materials.