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EARTH LAYERS
6.5B, 6.10AB Earth's Elements, Layers, & Rocks
Term | Definition |
---|---|
INNER CORE | Sphere of solid nickel & iron at the center of Earth; surrounded by liquid outer core. |
OUTER CORE | Outer layer of Earth’s core; surrounds inner core; made of liquid nickel & iron. |
MANTLE | Solid layer of Earth between the crust & core; made of dense silicates. |
CRUST | Thin, solid outermost layer of Earth; made of less dense silicates; either continental (landmasses) or oceanic (ocean floors). |
LITHOSPHERE | Cool, rigid, outermost layer of Earth that consists of the crust & uppermost part of the mantle; broken into pieces or segments called plates; litho = rock. |
ASTHENOSPHERE | Solid layer with plasticity in upper mantle located just below the lithosphere; lithospheric plates “float” & move on this layer; astheno = weak. |
PLASTICITY | Characteristic of the material in the asthenosphere; existing in solid state yet having the ability to flow without being a liquid. |
EARTH'S LAYERS | Divisions of the composition of Earth determined by either chemical composition or by physical state of matter. |
CHEMICAL COMPOSITION | Types, quantities, & arrangements of elements that make up a substance. |
PHYSICAL PROPERTIES | Measurable characteristics that describe physical state of something, including mass, magnetism, temperature, density, shape, volume, & conductivity. |
TEMPERATURE | Measure of the amount of heat energy. |
STATES OF MATTER | Distinct forms of matter known in everyday experience: solid, liquid, and gas; also referred to as phases of matter. |
PRESSURE | Force exerted on matter through contact with other matter; affects melting & boiling points. |
DENSITY | Amount of matter in a given space or volume; relationship between mass & volume; less dense matter will form layers above more dense matter. |
EARTH'S EVOLUTION | Process that formed & changed planet Earth from its beginning to the present. |
MINERAL COMPOSITION | Unique combination of solid elements & compounds that make up a mineral. |
ROCK CYCLE | Earth's rocks change from 1 type into another over time due to various Earth processes; changes occur in mineral compositions & physical structures. |
IGNEOUS ROCK | Formed when lava or magma cools & solidifies; lava (above ground) cools quickly & forms rocks with small crystals, while magma (below ground) cools slowly & forms rocks with larger crystals. |
LAVA | Molten rock or magma that has reached Earth's surface by volcanic action; characterized by small crystals due to rapid cooling on Earth's surface. |
MAGMA | Melted or molten rock material beneath Earth's surface; cools slowly to form rocks with larger crystals. |
METAMORPHIC ROCK | Formed deep underground where heat & pressure cause existing rocks to be changed in both mineral composition & structural characteristics. |
HEAT and PRESSURE | Changing variables due to the weight of overlying rocks, causing changes to rock characteristics & mineral composition, thus forming metamorphic rocks. |
SEDIMENTARY ROCK | Forms when particles of other rocks are deposited in layers & are compacted (crushed together), & cemented (binding of sediments). |
COMPACTION | Occurs when rock particles or sediments are pressed together or packed down by gravity & the pressure of overlying rock layers. |
CEMENTATION | Occurs when compacted sediments stick together & turn into rock. |
Element | Pure substance composed of the same type of atom throughout. |
Periodic Table of Elements | Table in which all the known elements are arranged by properties & are represented by 1 or 2 letters, referred to as chemical symbols. |
Lithosphere | Rigid outer layer of Earth made up of the uppermost part of the mantle & crust; litho = rock; sphere = globe |
Hydrosphere | All of the water on Earth; hydro = water; sphere = globe |
Biosphere | Sum of all living matter, made of a limited number of elements including oxygen, carbon, hydrogen, nitrogen, calcium, & phosphorus; bio = life; sphere = globe |
Atmosphere | Layer of gas surrounding planet Earth, held in place by gravity; composed of a limited number of elements, primarily nitrogen & oxygen; atmo = air; sphere = globe |
Matter | Anything that has mass & takes up space. |
Properties | Physical & chemical characteristics of matter used to describe or identify a substance. |
Mixture | Combination of 2 or more substances which do not chemically combine. |
Uniform Composition | Made of the same evenly distributed substance or combination of substances throughout; uni = one |