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Science 6th gr
Science stuff on everything learned in 6th grade
Question | Answer |
---|---|
What is a volcano? | a weak spot in the crust where magma has come to the surface |
What is silica? | a material found is magma that has formed from the elements oxygen and silicon |
What is tension? | force that pulls on the rock and stretches it until it breaks |
What is compression? | force that squeezes the rock until it folds or breaks |
What is shearing? | stress that pushes rock in opposite directions |
What is a normal fault? | made by tension; one block lies above the other; at an angle |
What is a reverse fault? | made by compression; blocks move in opposite direction from normal fault ex.) top block going up a mountain |
What is a strike-slip fault? | made by shearing; not at an angle; move from side to side |
What is a P wave? | smallest, first and last wave in an earthquake |
What is an S wave? | medium sized wave, second in an earthquake |
What is a surface wave? | largest and third wave in an earthquake |
What can P waves, S waves, and surface waves be classified as? | Seismic waves |
What does the Mercalli Scale measure? | rates earthquakes based on amount of damage done |
What does the Richter Scale measure? | rates an earthquake based on its size |
What does the Moment Magnitude Scale measure? | rates earthquake based on the amount of energy it releases |
What is an epicenter? | where the earthquake starts; three circles are drawn, where all circles meet |
What is a tiltimeter? | measures tilting or raising of the ground |
What is a creep meter? | uses wire stretched across fault to measure movement of the ground |
What is a laser-ranging device? | uses laser beam to detect horizon movements |
What is weathering? | the process that breaks down rock and other substances at Earth's surface |
What is erosion? | the removal of rock particles by wind, water, ice, or gravity |
What is uniformitarianism? | the principle that states that the same processes that operate today operated in the past |
What are the two kinds of weathering? | Mechanical weathering & Chemical weathering |
How does does weathering normally take? | Hundreds to thousands of years |
What kind the weathering called Release of Pressure do? | Mechanical Weathering; erosion causes rock to lose pressure, sheds top layer |
What kind of weathering is Freezing & Thawing? | Mechanical |
What kind of weathering id animal actions? | Mechanical |
What kind of weathering is plant growth? | Mechanical |
What kind of weathering is abrasion? | mechanical |
What is mechanical weathering? | rock is physically broken down into tiny pieces |
What is ice wedging? | water freezes and expands in a rock, creating cracks |
What is abrasion? | grinding away of rock by rock particles carried by water, ice, wind, gravity |
What is chemical weathering? | process that breaks down rock through chemical changes |
How does water weather rock? | water dissolves the rock |
How does oxygen weather rock? | creates rust through oxidation |
How does carbon dioxide weather rock? | creates weak acid rain when it mixes w/ water |
How can living organisms weather rock? | root create cracks and make them bigger |
How can acid rain weather rock? | chemicals pollute air and go u as clouds to rain down on rock and dissolve it |
What is permeable? | material is full of tiny connected air spaces that allow water to seep through |
Does climate affect the time it takes to wear down rock? | Yes |
Does the type of rock matter to the amount of time it takes to weather? | Yes |
What is soil? | the loose, weathered material on Earth's surface in which plants can grow |
What is bedrock? | the solid layer of rock beneath the soil |
What is humus(not the dip)? | dark-colored substance that forms as plant and animal remains decay |
What does fertility mean? | measure of how well soil supports plant growth |
What is the smallest soil particle size? | With 1/256 mm, clay |
What is the largest soil particle size? | With a size of 2 mm and larger, gravel |
How does soil form? | rock is broken down and mixed with other materials on the surface, such as humus |
What is a soil horizon? | a layer of soil that differs in color and texture from the layers above and below it |
What is topsoil? | crumbly dark brown soil that is a mixture of humus, clay and other materials |
What is subsoil? | usually consists of clay and other particles washed down from the A horizon, or topsoil |
Which weathers faster, limestone or granite? | limestone |
Which soil horizon forms first? | C horizon, large particles of bedrock |
Which soil horizon forms second? | A horizon, plants and soil |
Which soil horizon forms last? | B horizon, clay |
What is the process that splits rock through freezing and thawing? | ice wedging |
What type of weathering does acid rain result in? | chemical weathering |
What kind of soil is made up of roughly equal parts of sand, silt, and clay? | loam |
What soil horizon is made up of subsoil? | B horizon |
What produces the humus in soil? | decomposers |
What is mechanical weathering? | the removal of rock particles by gravity, water, wind, or ice |
Why does rock that is permeable weather easily? | because it is full of tiny air holes |
What is the decayed organic material in soil? | humus |
What is the layer of plant litter that remains at the surface of the soil? | litter |
What is conservation plowing? | farmers conserve soil fertility by leaving dead stalks and weeds in the ground |
What is the principle of uniformitarianism? | what happens in the present has happened in the past |
How can plants act as agents for mechanical weathering? | Plant growth through rocks |
How can plants act as agents for chemical weathering? | they produce weak acids |
How can oxygen be an agent of chemical weathering? | oxidation, rust |
How can carbon dioxide be an agent for chemical weathering? | carbonic acid, weak rain |
How does soil form? | rock weathers and mixes with humus and other organic materials |
Which soil horizon has the most fertility and humus? | Horizon A |
Which animal does most of the work in mixing humus into the soil? | Earthworms |
How can grass conserve soil? | roots hold soil in its place |
Name three types of mechanical weathering | Options: Abrasion Ice Wedging Plant Growth Pressure Release Animal Actions |
What type of mechanical weathering can be modeled using sandpaper? | Abrasion |
What kind of climate will limestone weather the fastest in? | Hot, wet climate |
What is sediment? | material moved by erosion |
What is deposition? | agents of erosion deposit sediment |
What does deposition do? | changes the shape of the land |
What three agents work together? | Weathering, erosion, deposition |
What is gravity? | the force that moves rock and any other materials downhill |
What is mass movement? | any one of several processes that move sediment down a hill |
What are the different kinds of mass movement? | slump, creep, mudflow, landslide |
What is a landslide? | occurs when soil and rock move quickly |
What is runoff? | water that moves over Earth's surface |
What is a rill? | tiny groove in the soil |
What is a gully? | large groove or channel int the soil that carries runoff ONLY AFTER A RAINSTORM |
What is a stream? | channel along which water is ALWAYS flowing down a slope |
What is a river? | large stream |
What is tributary? | stream or river that flows into a larger river |
What is a floodplain? | wide, flat area of land along a river |
What are rapids? | areas of turbulence below waterfalls where water rushes over rocks |
What is a meander? | loop-like bend in the course of a river |
What is an oxbow lake? | meander that has been cut off from a river |
What is an alluvial fan? | wide sloping deposit of sediment formed where a stream leaves a mountain/mountain range |
What is a delta? | sediment deposited where a river enters a still body of water that rises up to make a landform |
What is stalactite? | deposit that hangs like an icicle from the ceiling of a cave |
What is stalagmite? | cone-shaped deposit rising from the floor of a cave |
What is a fossil? | preserved remains or traces of of loving things |
What is sedimentary rock? | type of rock the is made up of hardened sediment |
What are some fossils found in rock? | molds, casts, petrified fossils, carbon films, trace fossils |
What can fossils be preserved in? | amber, tar, sedimentary rock, ice |
What is a mold? | hollow area in sediment in the shape of an organism or part of an organism |
What is a cast? | solid copy of the shape of an organism |
What is a petrified fossil? | fossils in which minerals replace all or part of an organinsm |
What is a carbon film? | extremely thin coating of carbon on rock |
What is a trace fossil? | fossil that provides evidence of the activities of ancient organisms |
What is a paleontologist? | scientist who studies fossils |
What is a scientific theory? | well-tested concept that explains a wide range of observations |
What is evolution? | gradual change in living things over time |
What does it mean to be extinct? | something no longer exists and will never again live on Earth |
What is relative age? | age of rock compared to ages of other rocks |
What is absolute age? | number of years since the rock formed. |
What is the law of superposition? | theory used to determine the relative ages of rock layers |
What is extrusion? | lava that hardens on the surface |
What is intrusion? | magma the cools and hardens into igneous rock |
What is unconformity? | surface where new rock layers meet older rock layers |
What are atoms? | tiny particles |
What is an element? | when all the same atoms are in a substance |
What is radioactive decay? | elements break down and release particles |
What is an element's half-life? | time it takes for half the radioactive element to decay |
What is the geologic time scale? | record of life forms in Earth's history |
What is an era? | long unit of time |
What is a period? | units of geologic time, not as long as eras |
What is a comet? | ball of dust and ice the orbits the sun |
What is continental drift? | continents move little by little |