Download 6th Grade Science Content Vocabulary

6th Grade Science Content Vocabulary
The Universe Key Terms
Scientific models - is a scientific activity the aim of which is to make a particular part or feature
of the world easier to understand, define, quantify, visualize, or simulate
Geocentric - having or relating to the earth as center
Heliocentric - having or relating to the sun as center
Big Bang Theory - the Big Bang is a THEORY about the creation of the UNIVERSE
Big Crunch Theory- a theory that says that the universe will stop expanding outward, reverse
direction, and pull back on itself to the single point
Nebular Hypothesis - the theory that the solar system evolved from a mass of nebular matter
Milky Way - the galaxy to which Earth and other components of our Solar System belong
Gravity - the force that pulls an apple to the ground, pulls the moon toward Earth, keeps the
planets in orbit and attract objects towards each other
Law of Universal Gravitation - states that every object in the universe attracts every other
object
Mass - the amount of matter in an object
Weight - the measure of the force of gravity on an object
Comet - a ball of ice and dust who orbits around the sun in a long, narrow ellipse
Asteroids- objects revolving around the sun that are too small and too numerous to be
considered planets
Meteors - the streak of light in the sky produced by the burning of a meteoroid in Earth's
atmosphere
Meteorite- when a meteoroid burns in the atmosphere and hits the ground
Meteoroid - a chunk of rock or dust in space that comes from comets or asteroids
Planet - any consolidated, large object which orbits a star
Revolution - the movement of one object around another, Earth around the sun, year; 365 1/4
days
Rotation - the spinning of the Earth on its axis, day and night (24 hours)
Celestial Sphere - giant spinning dome that the Greeks thought surrounded the Earth
Core - also called the Solar Core, is considered to extend from the center to about 0.2 to
0.25 solar radius. It is the hottest part of the Sun and of the Solar System. It is approx.
15,000,000°C if we convert that to Farhenheit that would be 27,000,000°F
Photosphere - the visible surface of the Sun; the upper surface of a convecting layer of gases in
the outer portion of the sun whose temperature causes it to radiate light at visible wavelengths;
sunspots and faculae are observed in the photosphere
Corona - the outer atmosphere of the Sun made up of thin gases and can only be seen during a
solar eclipse without telescopes its temperature is 1 - 2,000,000°C
Chromosphere - the lower level of the solar atmosphere between the photosphere and the
corona
Solar Wind - streams of charged particles constantly given off by the Sun
6th Grade Science Content Vocabulary
Solar System Key Terms
asteroid - an irregularly shaped rock that orbits the Sun.
comet - a space object made of ice and dust that orbits a star and develops a long, bright tail as it
nears its star.
core - the center of an object.
crater - a hole in the ground caused by the impact of an object from space.
dwarf planet - a nearly round object that orbits a star, is smaller than a planet, and is not a
satellite of another object.
gas giant - a large planet that is mainly made up of gases.
gravity - the force that pulls all objects toward each other.
moon - a huge ball of rock that travels around a planet; a natural satellite.
orbit - to revolve around another object.
planet - a very large object that orbits a star.
satellite - a natural or human-made object that orbits Earth or another object in space.
solar system - a group of objects in space that orbit a star.
star - a body in outer space, made of hot gases, that shines in the night sky.
terrestrial - like Earth; describes planets that are rocky and Earthlike in size.
asteroid belt - the area in space between Mars and Jupiter where most asteroids orbit.
atmosphere - a layer of gases surrounding a planet, star, or moon.
gas - a substance with no fixed volume or shape that can expand freely.
helium - the second lightest chemical element; often a gas.
hydrogen - the lightest chemical element; often a gas.
mass- the measure of the amount of matter in an object.
methane - a colorless, odorless, flammable gas commonly called "natural gas".
oxygen - a gas that has no color, taste, or smell, and which people need to live.
6th Grade Science Content Vocabulary
Earth, Moon and Sun Key Terms
asteroid - an irregularly shaped rock that orbits the Sun.
comet - a space object made of ice and dust that orbits a star and develops a long, bright tail as it
nears its star.
core - the center of an object.
crater - a hole in the ground caused by the impact of an object from space.
dwarf planet - a nearly round object that orbits a star, is smaller than a planet, and is not a
satellite of another object.
gas giant - a large planet that is mainly made up of gases.
gravity - the force that pulls all objects toward each other.
moon - a huge ball of rock that travels around a planet; a natural satellite.
orbit - to revolve around another object.
planet - a very large object that orbits a star.
satellite - a natural or human-made object that orbits Earth or another object in space.
solar system - a group of objects in space that orbit a star.
star - a body in outer space, made of hot gases, that shines in the night sky.
terrestrial - like Earth; describes planets that are rocky and Earthlike in size.
asteroid belt - the area in space between Mars and Jupiter where most asteroids orbit.
atmosphere - a layer of gases surrounding a planet, star, or moon.
gas - a substance with no fixed volume or shape that can expand freely.
helium - the second lightest chemical element; often a gas.
hydrogen - the lightest chemical element; often a gas.
mass- the measure of the amount of matter in an object.
methane - a colorless, odorless, flammable gas commonly called "natural gas".
oxygen - a gas that has no color, taste, or smell, and which people need to live.
6th Grade Science Content Vocabulary
Water on Earth Key Terms
Water vapor - The invisible, gaseous form of water.
Groundwater - Water that fills the cracks and pores in underground soil and rock layers.
Water cycle - The continuous process by which water moves from Earth's surface to the
atmosphere and back, passing through the living and nonliving parts of the environment.
Evaporation - The process by which molecules at the surface of a liquid, such as water, absorb
enough energy to change to a gaseous state, such as water vapor.
Transpiration - The process by which plants release water vapor through their leaves.
Precipitation - Forms of water such as rain, snow, sleet, or hail that fall from clouds and reach
Earth's surface.
Irrigation - The process of supplying water in areas of land to make them suitable for growing
crops.
Aquifer - An underground layer of rock or soil that holds water.
Wave - The movement of energy through a body of water.
Crest - The highest point of a wave.
Wavelength - The horizontal distance between two wave crests.
Frequency - The number of waves that pass a specific point in a given amount of time.
Trough - The lowest point of a wave.
Wave height - The vertical distance from the crest of a wave to the trough.
Tides - The daily rise and fall of Earth's waters on shores.
Spring tide - A tide with the greatest difference between high and low tide that occurs when the
sun and the moon are aligned in a line with Earth.
Neap tide - A tide with the least difference between low and high tide that occurs when the sun
and moon pull at right angles to each other.
Continental shelf - A gently sloping, shallow area of the ocean floor that extends outward from
the edge of a continent.
Continental slope - An incline leading down from the edge of the continental shelf.
Mid ocean ridge - The undersea mountain chain where new ocean floor is produced; a divergent
plate boundary.
Trench - A deep canyon in the ocean floor.
Estuary - A coastal inlet or bay where fresh water mixes with salty ocean water.
Surface current - Horizontal, streamlike movements of water that occur at or near the surface.
6th Grade Science Content Vocabulary
Weather and Climate Key Terms
atmosphere - Mixture of gases that surrounds Earth.
air pressure - The weight of air pressing down on an area.
troposphere - The bottom layer of the Earth's atmosphere.
stratosphere - The layer of the atmosphere in which ozone is present.
mesosphere - The layer of atmosphere where air is thin and most meteors burn up.
thermosphere - The outer most layer of the atmosphere.
radiation - The direct transfer of energy by electromagnetic waves.
conduction - The transfer of thermal energy that results from the collision of particles.
thermal energy - The total energy of motion in the molecules of a substance.
convection - The transfer of thermal energy through liquids and gases.
global warming - Is the rise in the average temperature of Earth's atmosphere and oceans since
the late 19th century and its projected continuation.
greenhouse effect - The process by which gases hold heat in the air.
temperature - The average amount of energy of motion of each molecule of a substance; a
measure to determine a substances level of hot or cold.
global winds - Winds that blow steadily from specific directions over long distances.
local winds - Winds that blow over short distances.
coriolis effect - The way Earth's rotation makes winds in the Northern Hemisphere curve to the
right and winds in the Southern Hemisphere curve to the left.
water cycle - The natural sequence through which water passes into the atmosphere as water
vapor, precipitates to earth in liquid or solid form, and ultimately returns to the atmosphere
through evaporation.
jet stream - A high-speed, meandering wind current, generally moving from a westerly direction
at speeds often exceeding 400 kilometers (250 miles) per hour at altitudes of 10 to 15 kilometers
(6 to 9 miles).
humidity - A measure of the amount of water vapor in the air.
relative humidity - A comparison of the actual amount of moisture in the air to the greatest
possible amount that could be in the air at the same temperature and pressure.
evaporation - The change of water from liquid water to water vapor.
condensation - The process by which water vapor changes from a gas to a liquid.
cumulus - Clouds that form less than 2 kilometers above the ground and look like fluffy,
rounded piles of cotton.
stratus - Clouds that form in flat layers.
cirrus - Wispy, feathery clouds made mostly of ice crystals that form at high levels, above about
6 kilometers.
barometer - An instrument that is used to measure air pressure and predict changes in the
weather.
Meteorologist - A science that deals with the atmosphere and with weather.
precipitation - The liquid water that returns to Earth's surface, usually as rain or snow.
air mass - A huge body of air that has similar temperature, pressure, and humidity throughout.
front - The border between two air masses that collide.
climate - The average, year-after-year conditions of temperature, precipitation, winds, and
clouds in an area.
anemometer - An instrument used to measure wind speed.
6th Grade Science Content Vocabulary
thunderstorm - A very strong storm with a lot of rain, thunder, and lightning.
tornado - An intense windstorm that often forms within a severe thunderstorm.
hurricane - A large, spiraling storm system that can be a much as 600 km across.
heat - The transfer of thermal energy.
6th Grade Science Content Vocabulary
Plate Tectonics Key Terms
lithosphere - the outer part of the earth, consisting of the crust and upper mantle, approximately
100 km thick
asthenosphere - a zone of the earth's mantle that lies beneath the lithosphere and consists of
several hundred kilometers of deformable rock
convection current - current in Earth's mantle that transfers heat in Earth's interior and is the
driving force for plate tectonics
density - the mass per unit volume of a substance under specified conditions of pressure and
temperature
basalt - a hard, dense, dark volcanic rock
magnetic field - a condition found in the region around a magnet or an electric current
crust - outermost solid part of the earth
mantle - the layer of the earth between the crust and the core
upper mantle - the portion of the mantle below a depth of about 600 miles
inner core - the central part of the earth's core
outer core - the upper zone of the earth's core
oceanic plates – a thick mass of igneous rock which lies under the ocean floor
continental plates – thick continental crust
fossil – a remnant or trace of an organism or a past geologic age
pangea – a hypothetical supercontinent that included all the landmasses of the earth before the
Triassic Period
Theory of Tectonic Plates – describes the large scale motions of earth's lithosphere
tectonic plates – any one of the internally rigid crustal blocks of the lithosphere which move
horizontally across the earth's surface relative to one another
continental drift – the movement, formation, or re-formation of continents described by the
theory of plate tectonics
convergent boundary - tectonic plates collide with each other
divergent boundary - tectonic plates are moving away from each other
transform boundary - tectonic plates are not moving directly toward or directly away from each
other but rather two tectonic plates grind past each other in a horizontal direction
6th Grade Science Content Vocabulary
Rocks & Minerals Key Terms
igneous rock - a type of rock that forms from the cooling of molten rock at or below the surface
sedimentary rock - a type of rock that forms when particles from other rocks or the remains of
plants and animals are pressed and cemented together
metamorphic rock- a type of rock that forms from an existing rock that is changed by heat,
pressure, or chemical reactions
rock cycle - a slow process that recycles rocks
fossil - are the preserved remains or traces of animals, plants, and other organisms from the
remote past
lithification - the process in which sediments compact under pressure, fluids fill in between
spaces of particles crystallize and create rock by cementation
sediment - bits of sand, rocks, shells, dirt
extrusive - igneous rock that formed outside of the Earth
intrusive - igneous rock that formed inside the Earth
cleavage - to break into a smooth surface
mineral - a natural inorganic substance with a definite chemical make up
granite - common intrusive igneous rock
basalt - the most common igneous rock made from lava
gritty - small hard particles of stone
crystallized - to form or cause to form crystals
molten - made liquid by great heat
atoms - the smallest particle of an element
element - one of the simple substances, such as gold iron, carbon, sulfur, oxygen and vapors
graphite - one of the softest minerals able to leave a mark
stone - chalky sedimentary rock
gypsum - sedimentary rock formed by evaporation of salt water
zinc - ore found in deposits of sedimentary volcanic rocks
ore - source of most useful metals
conglomerate - rounded rocks (pebbles, boulders) cemented together in a matrix
compaction - the process that presses sediments together
cementation - the process in which dissolved minerals crystallize and glue particles of sediment
together
6th Grade Science Content Vocabulary
Weathering, Erosion and Soil Key Terms
weathering - any of the chemical or mechanical processes by which rocks exposed to the
weather undergo changes in character and break down
mechanical weathering - any of the destructive effects of the atmosphere and the exposure of
rocks to the extremes of the surface
chemical weathering - chemical effects of water, carbon dioxide, and oxygen attacking and
destroying the minerals that are near the surface of the Earth
frost wedging - a collective term for several mechanical weathering processes induced
by stresses created by the freezing of water into ice
exfoliation - the sheeting of rocks and their disintegration, thought to be due to thermal
expansion, at least on small structures
oxidation - the absorption by a mineral of one or more oxygen ions. The major type of chemical
weathering, particularly in rocks containing iron
acid rain - acid precipitation falling as rain
weathering rates - a measurement of the amount of weathering over a given time period
surface area - measurement of the extent of the area covered by a surface
topography - detailed, precise description of a place or region
climate - the meteorological conditions, including temperature, precipitation, and wind, that
characteristically prevail in a particular region
soil - the top layer of the Earth's surface, consisting or rock and mineral particles mixed with
organic matter
soil profile - the vertical section of soil showing the nature and sequence of the various layers, as
developed by deposition or weathering, or both
soil horizon - a layer of soil, approximately horizontal, which differs in structure and
composition from the adjacent layers
humus - the amorphous, ordinarily dark colored, colloidal matter in soil; a complex of the
fractions of organic matter of plant, animal, and microbial origin that are most resistant to
decomposition
regolith - the layer of loose rock resting on bedrock, constituting the surface of most land
parent bedrock - the original rock from which something else was formed
deposition - the dropping of material which has been picked up and transported by wind, water,
or ice
erosion - a group of natural processes, including weathering, dissolution, abrasion, corrosion,
and transportation, by which material is worn away from the Earth's surface
rill erosion - the formation of numerous, closely spaced rills due to the uneven removal of
surface soil by stream-lets of running water
gully erosion - erosion of soil by running water
wave erosion - erosion of the ocean floor by sediment moved by ocean waves
glacial erosion - movement of soil or rock from one point to another by the action of the moving
ice of a glacier
dust bowl - a region reduced to aridity by drought and dust storms
mass movement - the movement downslope of rock fragments and soil under the influence of
gravity
slides - a form of mass movement in which material slides in a relatively straight plane
flows - the mass movement of material held in suspension by water
6th Grade Science Content Vocabulary
creeps - the slow movement of rock debris and soil down a weathered slope
abrasion - the process of wearing down or rubbing away by means of friction
deflation - the erosion of soil by the wind
ventifact - a stone that has been shaped, polished, or faceted by wind-driven sand
deforestation - the act process of removing trees from or clearing a forest
erosion - a group of natural processes, including weathering, dissolution, abrasion, corrosion,
and transportation, by which material is worn away from the Earth's surface
tillage erosion - erosion that moves soil from the top of the field downward, exposing subsoil at
the crest while burying soil at the bottom
contour farming - cultivation of land along lines connecting points of equal elevation, to
prevent water erosion
slash and burn - a form of agriculture in which an area of forest is cleared by cutting and
burning, and is then planted, usually for several seasons, before being left to return to forest
fallowing - plowed but left unseeded during a growing season
soil conservation - management of soil to prevent or reduce soil erosion and depletion by wind
and water
terracing - a method of shaping land to control erosion on slopes of rolling land used for
cropping and other purposes
strip cropping - the growing of a cultivated crop, such as cotton, and a sod-forming crop, such
as alfalfa, in alternating strips following the contour of the land, in order to minimize erosion
contour plowing - farming practice of plowing across a slope following its elevation contour
lines
no-till farming - cultivation technique in which the soil is disturbed only along the slit or hole
into which seeds are planted
wind breaks - a hedge, fence, or row of trees serving to lessen or break the force of the wind
ground cover - a low-growing dense growth of plants planted to prevent soil erosion in areas
where turf is difficult to grow, as in deep shade, or on a steep slope
6th Grade Science Content Vocabulary
Resources and Human Impact on Earth Key Terms
desertification - is the expansion of desert conditions in areas where the natural plant cover has
been destroyed
pollutant - harmful material that can enter the biosphere through land, water, or air
acid rain - rain containing nitric and sulfuric acids caused by burning fossil fuels
conservation - the wise management of natural resources, including the preservation of habitats
and wildlife
smog - a mixture of chemicals (smoke + fog) that occurs as a gray-brown haze in the atmosphere
ozone layer - atmospheric layer in which ozone (03) gas is relatively concentrated which
protects us from the sun's ultra-violet radiation
alternative energy - energy generated in ways that do not deplete natural resources or harm the
environment, esp. by avoiding the use of fossil fuels and nuclear power
greenhouse effect - natural process in which atmospheric gases trap energy from sunlight as heat
deposition - is the geological process by which sediments, soil, and rocks are added to a
landform or land mass.
sustainable development - way of using natural resources without depleting them and of
providing for human needs without causing long term harm to the environment
renewable - a necessity of life (resource) which can regenerate quickly and that is replaceable;
Ex: trees, water
nonrenewable - a necessity of life (resource) which can NOT be replenished by natural means;
Ex: fossil fuels
monoculture - farming strategy in which large fields are planted with a single crop variety year
after year
thermal energy (or heat): the ability to do work through the release of heat
Internal energy - the energy associated with molecular motion (or temperature)
latent energy - the energy associated with the evaporation/condensation of water vapor
kinetic energy : the ability to do work due to motion
gravitational (or potential) energy: the ability to do work through changes in a body's location
within a gravitational field
electromagnetic wave energy: energy embedded in electromagnetic wave motion (such as
light, microwaves, or x-rays). when this kind of energy impinges on matter part or all of is
converted to heat
chemical energy: the ability to do work via a chemical interaction (i.e., change in molecular
structure)
energy - the ability to do work or cause change
nuclear fission - the splitting of an atom's nucleus into smaller nuclei
nuclear fusion - the combining of two atomic nuclei into a single larger nucleus, as when two
hydrogen atoms join together to form helium, releasing energy
heat - the energy transferred from a hotter object to a cooler one
heat transfer - the movement of energy from a warmer object to a cooler object
chemical energy - that part of the energy in a substance that can be released by a chemical
reaction
nuclear energy - the energy released by a nuclear reaction, especially by fission or fusion
kinetic energy - the energy possessed by a body because of its motion, equal to one half the
mass of the body times the square of its speed
6th Grade Science Content Vocabulary
potential energy - the energy of a particle or system of particles derived from position, or
condition, rather than motion. A raised weight, coiled spring, or charged battery has potential
energy
Law of Conservation of Energy - the fundamental principle of physics that the total energy of
an isolated system is constant despite internal changes
geothermal energy - heat energy in Earth's interior from water or steam that has been heated by
magma
solar energy - energy obtained from solar power