Download Physical Science Vocabulary Glossary

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Physical Science Vocabulary Glossary (7th Grade)
Abiotic factor (17): A nonliving part of an organism’s habitat.
Absolute brightness (10): The brightness a star would have if it were at a standard distance from Earth.
Acid rain (07): Rain or other form of precipitation that is more acidic than normal, caused by the release
of molecules of sulfur dioxide and nitrogen oxide into the air.
Accretion (09): The process of building something up gradually by the gathering together of smaller
pieces.
Adaptation (15): A characteristic of an organism that increases its chances of survival in its environment.
Allele (16): Any of two or more alternate forms of a gene that an organism may have for a particular trait.
Apparent brightness (10): The brightness of a star as seen from Earth.
Aquifer (08): An underground layer of rock or sediment that holds water.
Artesian well (08): A well in which water rises because of pressure within the aquifer.
Asteroid (13): One of the non-spherical rocky objects revolving around the sun that are too small and
numerous to be considered planets.
Asteroid belt (13): The region of the solar system between the orbits of Mars and Jupiter, where many
asteroids are found.
Asthenosphere (01): The soft layer of the mantle on which the lithosphere floats.
Astronomical unit (12): A unit of distance equal to the average distance between Earth and the sun,
about 150 million kilometers (or 93 million miles).
Autotroph (19): An organism that is able to capture energy from sunlight or chemicals and use it to
produce its own food; a producer.
Axis (14): An imaginary line that passes through a planet’s center and its north and south poles, about
which the planet rotates.
Batholith (05): A mass of rock formed when a large body of magma cools inside the crust.
Biodiversity (15): The total number of different species on earth (or in a particular area).
Biome (17): A major ecological community type (examples include rainforest, desert, coral reef, tundra,
deciduous forest, savannah, etc).
Biotic factor (17): A living or once living part of an organism’s habitat.
Black hole (10): An object whose gravity is so strong that nothing, not even light, can escape.
Physical Science Vocabulary Glossary
Caldera (05): The large hole at the top of a volcano formed when the roof of a volcano’s magma chamber
collapses.
Calendar (14): A system of organizing time that defines the beginning, length, and divisions of a year.
Carnivore (17): A consumer that obtains energy by eating only animals.
Carrying capacity (18): the largest population that an area can support.
Cast (03): A fossil that is a solid copy of an organism’s shape formed when minerals seep into a mold.
Cellular respiration (19): The process in which oxygen and glucose (a type of sugar) undergo a complex
series of chemical reactions inside cells, releasing energy.
Cementation (02): The process by which dissolved minerals crystallize and glue particles of sediment
together into one mass.
Chlorofluorocarbons (07): Human-made gases containing chlorine and fluorine (also called CFCs) that
are the main cause of ozone depletion.
Chlorophyll (19): A green pigment found in the chloroplasts of plants, algae, and some bacteria that is
involved in photosynthesis.
Chromosphere (11): The middle layer of the sun’s atmosphere.
Coma (of a comet) (13): The fuzzy outer layer of a comet.
Comet (13): A loose collection of ice and dust that orbits the sun, typically in a long, narrow orbit.
Commensalism (18): a type of relationship between two species of a plant, animal, fungus, etc., in which
one lives with, on, or in another without damage to either.
Community (17): All the different populations that live together in a particular area.
Compaction (02): The process by which sediments are pressed together under their own weight.
Competition (18): the struggle between organisms to survive as they attempt to use the same limited
resources.
Compression (06): Stress that squeezes rock until it folds or breaks.
Condensation (19): The process by which water is changed from a gas (water vapor) to a liquid; a stage
of the water cycle.
Conduction (01): The transfer of thermal energy from one particle of matter to another.
Consumer (17): an organism in a food chain that obtains nutrients from producers or other consumers;
consumers may be herbivores, carnivores, or omnivores.
Continental drift (04): The hypothesis that the continents slowly move across Earth’s surface.
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Physical Science Vocabulary Glossary
Convection current (01): The movement of a fluid (a liquid or a gas) caused by differences in
temperature, that transfers heat from one part of the fluid to another.
Convection (Convective) zone (11): The outermost layer of the sun’s interior.
Convergent boundary (04): A plate boundary where two plates move toward each other.
Core (11): The central region of the sun, where nuclear fusion takes place.
Corona (11): The outermost layer of the sun’s atmosphere that extends for millions of kilometers; only
visible to the naked eye during a solar eclipse; source of solar wind.
Crater (05): A large, round pit caused by the impact of a meteoroid.
Crust (01): The layer of rock that forms Earth’s outer surface.
Decomposers (17): organisms that break down wastes and dead organisms and return the raw materials to
the soil.
Deep-ocean trench (04): A deep valley along the ocean floor beneath which oceanic crust slowly sinks
toward the mantle.
Deforestation (07): The action of clearing the forests.
Density (01): The measurement of how much mass of a substance in contained in a given volume; the
compactness of the particles in a substance.
Deposition (02): The process by which sediment is laid down in new locations.
Desertification (07): The advance of desert-like conditions into areas that previously were fertile; caused
by overfarming, overgrazing, drought, and climate change.
Divergent boundary (04): A plate boundary where two plates move away from each other.
DNA (15): A substance that carries genetic information in the cells of plants and animals. DNA stands for
deoxyribonucleic acid.
DNA replication (16): The process in which an identical copy of DNA strand is formed for a new cell.
Dominant allele (16): The form of a trait that is expressed or shown when the combination of alleles for
this trait is heterozygous.
Dormant (05): Not currently active but able to become active in the future (as with a volcano).
Drought (07): A long period of lower than normal precipitation for the area.
Dwarf planet (12): An object that orbits the sun and is spherical, but has not cleared the area of its orbit.
Earthquake (06): The shaking that results from the movement of rock beneath Earth’s surface.
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Physical Science Vocabulary Glossary
Eclipse (14): The partial or total blocking of one object in space by another.
Ecology (17): the study of how organisms interact with each other and their environment.
Ecosystem (17): The living and once living organisms in a particular area along with their nonliving
environment.
Ellipse (13): An oval shape, which may be elongated or nearly circular; the shape of the planets’ orbits.
Elliptical galaxy (09): A galaxy shaped like a round or flattened ball, generally containing only old stars.
Emissions (07): Pollutants that are released into the air.
Endangered species (15): A species whose population is so small that it is in danger of extinction.
Epicenter (06): The point on Earth’s surface directly above an earthquake’s focus.
Equinox (14): Either of the two days of the year on which neither hemisphere is tilted toward or away
from the sun.
Era (03): One of the three long units of geological time.
Erosion (02): The process by which water, wind, or gravity moves weathered particles of rock and soil to
a new location.
Eutrophication (08): The buildup over time of nutrients in freshwater lakes and ponds that leads to an
increase in the growth of algae.
Evaporation (19): the process by which water is changed from a liquid to a gas from the surface of the
liquid; a stage of the water cycle.
Evolution (15): The process by which modern organisms have descended from ancient organisms;
change over time.
Extinct (volcano) (05): A volcano that is no longer active and unlikely to erupt again.
Extinct species (15): A species that no longer exists.
Extinction (03): When all the members of a species disappear from Earth.
Extrusive rock (02): Igneous rock that forms from lava on Earth’s surface.
Fault (04): A crack in the earth’s crust along which movement of tectonic plates has occurred.
Fermentation (19): The process by which cells release energy by breaking down food molecules without
using oxygen.
Fertilization (16): the process by which the female reproductive cell (egg) is united with the male
reproductive cell (sperm or pollen).
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Physical Science Vocabulary Glossary
Fertilizer (07): A substance that provides nutrients to help crops grow better.
Focus (06): The point beneath Earth’s surface where rock first breaks under stress and causes an
earthquake.
Fossil (03): The preserved remains or traces of an organism that lived in the past.
Fossil fuels (07): Coal, oil, or natural gas that forms over millions of years from the remains of ancient
organisms; burned to release energy.
Galaxy (09): A huge group of single stars, star clusters, dust, and gas bound together by gravity.
Gas giant (12): The name often given to the outer planets: Jupiter, Saturn, Uranus, and Neptune.
Gene (15): A sequence of DNA that determines a trait and is passed from parent to offspring.
Genetics (16): the scientific study of heredity.
Geocentric (13): Term describing a model of the universe in which Earth is at the center of the revolving
planets.
Geologic time scale (03): A record of the geologic events and life forms in Earth’s history.
Greenhouse effect (12): The trapping of heat near a planet’s surface by certain gases in the planet’s
atmosphere.
Habitat (17): an environment that provides the things a specific organism needs to live, grow, and
reproduce.
Heliocentric (13): Term describing a model of the solar system in which Earth and the other planets
revolve around the sun.
Hemisphere (14): Half of the earth
Herbivore (17): A consumer that obtains energy by eating only plants.
Heredity (16): the passing of physical characteristics, or trait, from parents to offspring.
Hertzprung-Russel (HR) diagram (10): A graph relating the surface temperature and absolute
brightness of stars.
Heterotroph (19): An organism that cannot produce its own food.
Heterozygous (16): A cell or organism that has two different alleles for a particular trait.
Homologous structure (15): Similar structures that related species have inherited from a common
ancestor.
Homozygous (16): a type of cell or organism that has identical rather than different alleles for a particular
trait.
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Physical Science Vocabulary Glossary
Host (18): The organism that a parasite lives in or on.
HR (Hertzprung-Russel) diagram (10): A graph relating the surface temperature and absolute
brightness of stars.
Hybrid (16): An offspring of crosses that has two different alleles for a trait.
Igneous rock (02): A type of rock that forms from the cooling of molten rock at or below the surface of
the earth.
Impermeable (08): A characteristic of materials, such as clay and granite, through which water does not
easily pass.
Inherited trait (16): A trait or characteristic that is passed from parent to offspring.
Inner core (01): A dense sphere of solid iron and nickel at the center of the earth.
Intrusive rock (02): Igneous rock that forms when magma hardens beneath Earth’s surface.
Invertebrate (15): An animal that lacks a backbone
Irregular galaxy (09): A galaxy that does not have a regular shape.
Kuiper belt (13): A region where many small objects orbit the sun and that stretches from beyond the
orbit of Neptune to about 100 times Earth’s distance from the sun.
Land reclamation (07): The process of restoring land to a more natural, productive state.
Lava (05): Liquid magma that reaches the surface.
Lava flow (05): The area covered by lava as it pours out of a volcano’s vent.
Law of superposition (03): The geologic principle that states that in horizontal layers of sedimentary
rock, each layer is older than the layer above it and younger than the layer below it.
Law of universal gravitation (09): The scientific law that states that every object in the universe attracts
every other object.
Light-year (09): The distance that light can travel in a year (measures DISTANCE, not TIME).
Limiting factor (18): an environmental factor that causes a population to decrease in size.
Lithosphere (01): A rigid layer made up of the uppermost part of the mantle and the crust.
Lunar eclipse (14): The blocking of sunlight to the moon that occurs when earth is directly between the
sun and the moon.
Magma (05): The molten mixture of rock-forming substances, gases, and water from the mantle.
Magma chamber (05): The pocket beneath a volcano where magma collects.
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Physical Science Vocabulary Glossary
Magnitude (06): The measurement of an earthquake’s strength based on seismic waves and movement
along faults.
Mantle (01): The layer of hot, solid material between Earth’s crust and core.
Maria (12): Dark, flat areas on the moon’s surface formed from huge ancient lava flows.
Metamorphic rock (02): A type of rock that forms from an existing rock that is changed by heat,
pressure, or chemical reactions.
Meteor (13): A streak of light in the sky produced by the burning of a meteoroid in earth’s atmosphere.
Meteorite (13): A meteoroid that passes through the atmosphere and hits Earth’s surface.
Meteoroid (13): A chunk of rock or dust in space, generally smaller than an asteroid.
Mid-ocean ridge (04): An undersea mountain chain where new ocean floor is produced; a divergent plate
boundary under the ocean.
Mold (03): A type of fossil that is a hollow area in sediment in the shape of an organism or part of an
organism.
Moon (12): A natural object that orbits a planet.
Mutualism (18): A relationship between two species of organisms in which both benefit from the
association.
Natural resource (07): Anything naturally occurring in the environment that people use.
Natural selection (15): The process by which individuals that are better adapted to their environment are
more likely to survive and reproduce than other members of the same species.
Neap tide (14): The tide with the least difference between consecutive low and high tides.
Nebula (10): A large cloud of gas and dust in space.
Neutron star (10): The small, dense remains of a high-mass star after a supernova.
Niche (18): The unique position occupied by a particular species in terms of the area it inhabits and the
function it performs within the community.
Nuclear fusion (11): The process in which two atomic nuclei combine to form a larger nucleus, forming a
heavier element and releasing huge amounts of energy; the process by which energy is produced in stars.
Nucleus (of a comet) (13): The solid, inner core of a comet.
Nutrient (07): 1) substances in food that provide the raw materials and energy needed for an organism to
carry out its essential life processes. 2) a substance such as nitrogen or phosphorus that enables plants and
algae to grow.
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Physical Science Vocabulary Glossary
Nutrient depletion (07): The situation that arises when more soil nutrients are used than the decomposers
can supply.
Omnivore (17): A consumer that obtains energy by eating both plants and animals.
Oort cloud (13): A spherical region of comets that surrounds the solar system.
Orbit (09): The path of an object as it revolves around another object in space.
Organism (17): a living thing.
Outer core (01): A layer of molten iron and nickel that surrounds the inner core of Earth.
Ozone (07): A form of oxygen that has three oxygen atoms in each molecule instead of the usual two;
toxic to organisms where it forms near Earth’s surface.
Ozone layer (07): The layer of the upper atmosphere that contains a higher concentration of ozone than
the rest of the atmosphere.
Paleontologist (03): A scientist who studies fossils to learn about organisms that lived long ago.
Pangaea (04): The name of the single landmass that began to break apart 200 million years ago and gave
rise to today’s continents.
Parasite (18): the organism that benefits in a parasitic relationship.
Parasitism (18): a type of symbiosis in which one organism lives with, on, or in a host and harms it.
Period (03): One of the units of geologic time into which geologists divide eras.
Permeable (08): Characteristic of a material that contains connected air spaces, or pores, that water can
seep through easily.
Pesticide (08): A chemical that kills insects and other crop-destroying organisms.
Phase (14): One of the different apparent shapes of the moon as seen from Earth.
Photochemical smog (07): A brownish thick haze that is a mixture of ozone and other chemicals formed
when pollutants react with sunlight.
Photosynthesis (19): The process by which plants and other autotrophs capture and use light energy to
make food from carbon dioxide and water.
Photosphere (11): The inner layer of the sun’s atmosphere that gives off its visible light; the sun’s
surface.
Pipe (05): A long tube through which magma moves from the magma chamber to Earth’s surface.
Planet (09): An object that orbits a star, is large enough to have become rounded by its own gravity, and
has cleared the area of its orbit.
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Physical Science Vocabulary Glossary
Plate (04): A section of the lithosphere that slowly moves over the asthenosphere, carrying pieces of
continental and oceanic crust.
Plate tectonics (04): The theory that pieces of the Earth’s lithosphere (plates) are in constant motion,
driven by convection currents in the mantle.
Plateau (06): A large landform that has high elevation and a more or less level surface.
Population (17): All members of the same species living together at the same time in the same area.
Precipitation (19): a form of water (hail, rain, sleet, snow) that condenses in the atmosphere and falls to
earth’s surface.
Predation: (18): an interaction in which one organism kills another for food or nutrients.
Predator (18): An organism that obtains nutrients from other organisms; does the killing in a predation
interaction.
Pressure (01): The force pushing on a surface divided by the area of that surface.
Prey (18): An organism that is killed and eaten by another organism in a predation interaction.
Producer (17): An organism that makes its own food.
Prominence (11): A huge, reddish loop of gas that protrudes from the sun’s surface, linking parts of
sunspot regions.
Protostar (10): A contracting cloud of gas and dust with enough mass to form a star.
Punnett square (16): A chart that shows all the possible combinations of alleles that can result form a
genetic cross.
Purebred (16): the offspring of many generations that show the same form of a trait.
Radiation (01): The transfer of energy by electromagnetic waves.
Radiation (Radiative) Zone (11): A region of very tightly packed gas in the sun’s interior where energy
is transferred mainly in the form of electromagnetic radiation.
Radiative (Radiation) Zone (11): A region of very tightly packed gas in the sun’s interior where energy
is transferred mainly in the form of electromagnetic radiation.
Radioactive dating (03): Measurement of the amount of radioactive material that an object contains; can
be used to estimate the age of an object.
Radioactive decay (03): The process in which radioactive elements break down, releasing fast-moving
particles and energy.
Recessive allele (16): An allele that is hidden whenever the dominant allele is present.
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Physical Science Vocabulary Glossary
Reservoir (08): A lake that stores water for human use.
Revolution (14): The movement of an object around another object.
Richter scale (06): A scale that rates an earthquake’s magnitude based on the size of its seismic waves.
Rift valley (04): A deep valley that forms where two plates move apart.
Ring (12): A thin disk of small ice and rock particles surrounding a planet.
Ring of Fire (05): A major belt of volcanoes that rims the Pacific Ocean.
Rock cycle (02): A series of processes on the surface and inside Earth that slowly changes rocks from one
kind to another.
Rotation (14): The spinning motion of a planet on its axis.
Satellite (12): A natural or man-made object that orbits a planet or moon or any other astronomical body.
Saturated zone (08): The area of permeable rock or soil in which the cracks and pores are totally filled
with water.
Scavenger (17): a carnivore that feeds on the bodies of dead organisms.
Scientific notation (09): A mathematical method of writing numbers using powers of ten.
Sea-floor spreading (04): The process by which molten material adds new oceanic crust to the ocean
floor.
Sediment (02): Small, solid pieces of material that some from rocks or the remains of organisms; earth
materials deposited by erosion.
Sedimentary rock (02): A type of rock that forms when particles from other rocks (sediment) or the
remains of plants and animals are pressed and cemented together.
Seismic wave (01): Vibrations that travel through Earth carrying the energy released during an
earthquake.
Seismogram (06): The record of an earthquake’s seismic waves produced by a seismograph.
Seismograph (06): A device that records ground movements caused by seismic waves as they move
through Earth.
Sewage (08): The water and human wastes that are washed down sinks, toilets, and showers.
Shearing (06): Stress that pushes masses of rock in opposite directions, in a sideways movement.
Solar eclipse (14): The blocking of sunlight to Earth that occurs when the moon is directly between the
sun and earth.
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Physical Science Vocabulary Glossary
Solar flare (11): An eruption of gas from the sun’s surface that occurs when the loops in the sunspot
regions suddenly connect.
Solar system (09): The system consisting of the sun and the planets and other objects that revolve around
it.
Solar wind (11): A stream of electrically charged particles that come from the sun’s corona.
Solstice (14): Either of the two days of the year on which the sun reaches its greatest distance north or
south of the equator.
Species (17): A group of the same kind of organisms that can mate and produce offspring that can
reproduce.
Spring tide (14): The tide with the greatest difference between consecutive low and high tides.
Spiral galaxy (09): A galaxy with a bulge in the middle and arms that spiral outward in a pinwheel
pattern.
Star (09): A ball of hot gas, primarily hydrogen and helium, which undergoes nuclear fusion.
Stress (06): A force that acts on a rock to change its shape or volume.
Subduction (04): The process by which oceanic crust sinks beneath a deep-ocean trench and back into the
mantle at a convergent plate boundary.
Sunspot (11): A dark, relatively cool, area of gas on the surface of the sun.
Supernova (10): The brilliant explosion of a dying supergiant star.
Symbiosis (18): Any relationship in which two species live closely together and that benefits at least one
of the species.
Temperature inversion (07): A condition in which a layer of warm air traps polluted air close to Earth’s
surface.
Tension (06): Stress that stretches rock so that it becomes thinner in the middle.
Terrestrial planet (12): The name often given to the four inner planets: Mercury, Venus, Earth, and
Mars.
Threatened species (15): A species that could become endangered in the near future.
Tide (14): The periodic rise and fall of the level of water in the ocean.
Trait (15): A specific characteristic that an organism can pass to its offspring.
Transform boundary (04): A plate boundary where two plates move past each other in opposite
directions.
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Physical Science Vocabulary Glossary
Transpiration (19): The passage of water through a plant from the roots through the vascular system to
the atmosphere; part of the water cycle.
Uniformitarianism (03): The geologic principle that the same geologic processes that operate today
operated in the past to change Earth’s surface.
Universe (09): All of space and everything in it.
Unsaturated zone (08): The layer of rocks and soil above the water table in which the pores contain air
as well as water.
Urbanization (07): The development of large land areas for cities.
Variation (15): any difference between individuals of the same species.
Vent (05): The opening through which molten rock and gas leave a volcano.
Vertebrate (15): An animal that has a backbone.
Virus (08): A non-living organic compound (made of carbon) that is not made of cells and must reside
inside of a host cell.
Volcano (05): A weak spot in the crust where magma has come to the surface.
Water cycle (19): The continuous movement of water through the environment by evaporation,
condensation, transpiration, precipitation, and runoff.
Water table (08): The top of the saturated some, or depth to the groundwater under Earth’s surface.
Water vapor (19): The gas state of water.
Watershed (08): The land area that supplies water to a river system.
Weathering (02): The process by which rocks and other surfaces are broken down.
Wetland (08): A land area that is covered with a shallow layer of water during some or all of the year.
White dwarf (10): The blue-white hot core of a star that is left behind after its outer layers have expanded
and drifted out into space.
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