Science Glossary Grade 4
adaptation
a characteristic of an organism that increases its chance of survival in its
environment
atmosphere
the layers of gas that surround Earth, other planets, or stars
atom
the smallest unit of a chemical element that can still retain the properties of
that element
axis
the imaginary line on which an object rotates (e.g., Earth’s axis runs through
Earth between the North Pole and the South Pole); an imaginary straight line
that runs through a body; a reference to the line in a coordinate system or
graph
carnivore
an animal or plant that consumes or obtains nutrients from animals
change of state
a physical change that occurs when matter changes to another state (i.e.,
liquid, gas, or solid)
chemical change
a reaction or a change in a substance produced by chemical means that results
in producing a different chemical
community
all the populations of organisms belonging to different species and sharing
the same geographical area
compound
a substance made up of a combination of two or more elements held together
by chemical bonds that cannot be separated by physical means; has properties
unlike those of the elements that make up the compound
condensation
the process of changing from a gas (i.e., water vapor) to a liquid (i.e., dew);
the act of making more dense or compact
conservation
controlled use and/or maintenance of natural resources; various efforts to
preserve or protect natural resources
constellation
a star pattern identified and named as a definite group; usually thought of as
forming certain shapes or figures in a specific region of the sky
consumer
an organism that feeds on other organisms for food
decomposer
any organism that feeds or obtains nutrients by breaking down organic matter
from dead organisms
density
concentration of matter of an object; number of individuals in the same
species that live in a given area; the mass per unit volume of a substance in a
given area
deposition
layering matter in a natural process
earthquake
the shaking of the ground caused by a sudden release of energy in Earth’s
crust
ecosystem
an integrated unit of a biological community, its physical environment, and
interactions
electricity
energy created by moving charged particles
element
a substance that cannot be reduced to a simpler substance by chemical means
energy
a quantity that describes the capacity to do work; a source of usable power
energy pyramid
a pyramidal diagram that compares the amount of energy available at each
position, or level, in the feeding order
energy transfer
a change of energy from one form to another (e.g., mechanical to electrical,
solar to electrical)
environment
the sum of conditions affecting an organism, including all living and
nonliving things in an area, such as plants, animals, water, soil, weather,
landforms, and air
equator
an imaginary circle around Earth’s surface located between the poles and a
plane perpendicular to its axis of rotation that divides it into the Northern and
Southern Hemispheres
erosion
the wearing away of Earth’s surface by the breakdown and transportation of
rock and soil
evaporation
the process by which a liquid is converted to its vapor phase by heating the
liquid
experiment
a procedure that is carried out and repeated under controlled conditions in
order to discover, demonstrate, or test a hypothesis; includes all components
of the scientific method
food chain
transfer of energy through various stages as a result of feeding patterns of a
series of organisms
food web (food
cycle)
the interconnected feeding relationships in a food chain found in a particular
place and time
force
a quality that tends to produce movement or acceleration of a body in the
direction of its application; a push or pull
fossil
a whole or part of a plant or animal that has been preserved in sedimentary
rock
friction
a force that opposes the relative motion of two material surfaces in contact
with one another
fulcrum
the pivot point of a lever
galaxy
a large collection of stars, gases, and dust that are part of the universe (e.g.,
the Milky Way galaxy) bound together by gravitational forces
gas
one of the fundamental states of matter in which the molecules do not have a
fixed volume or shape
gravitation
a force of attraction between two masses
gravity
the observed effect of the force of gravitation
habitat
a place in an ecosystem where an organism normally lives
heat
a form of energy resulting from the temperature difference between a system
and its surroundings
herbivore
an animal that feeds on plants
igneous rock
a type of rock that forms from molten or partly molten material that cools and
hardens
inclined plane
a type of simple machine; a slanted surface that makes it easier to move a
mass from a lower point to a higher point
inertia
the property of a body, due to its mass, that causes it to resist any change in
its motion unless overcome by a force
investigation
a procedure that is carried out in order to observe a response caused by a
stimulus; not a complete experiment
kinetic energy
the energy possessed by a body because of its motion
lever
a type of simple machine; consists of a rigid bar that pivots about a fulcrum,
used to transmit and enhance power or motion
life cycle
the entire sequence of events in an organism’s growth and development
light
electromagnetic radiation that lies within the visible range
liquid
one of the fundamental states of matter with a definite volume but no definite
shape
magnetic
having the property of attracting iron and certain other materials by virtue of
a surrounding field of force
mass
the amount of matter an object contains
matter
a solid, liquid, or gas that possesses inertia and is capable of occupying space
metamorphic
rock
a type of rock that forms from existing rock because of extreme changes
caused by heat, pressure, or chemical environments
microscopic
relating to an object too small to be visible without the use of a microscope
mixture
the product of a thorough blending of two or more substances, not chemically
combined
moon
a natural satellite that revolves around a planet
moon phase
a phrase that indicates the fraction of the Moon’s disc that is illuminated (as
seen from Earth); the eight moon phases (in order): new moon, waxing
crescent, first quarter, waxing gibbous, full moon, waning gibbous, last
quarter, waning crescent
nonrenewable
resource
a resource that can only be replenished over millions of years
organ
a structure containing different tissues that are organized to carry out a
specific function of the body (e.g., heart, lungs, brain, etc.)
organism
any living plant, animal, or fungus that maintains various vital processes
necessary for life
photosynthesis
a chemical process by which plants trap light energy to convert carbon
dioxide and water into carbohydrates (sugars)
physical change
a reaction; a change in matter from one form to another, without forming new
substances
planet
a large body in space that orbits a star and does not produce light of its own
pollution
any alteration of the natural environment producing a condition harmful to
living organisms; may occur naturally or as a result of human activities
population
a group of organisms of the same species living in a specific geographical
area
potential energy
the energy an object has because of its position or structure; stored energy
predator
an organism that preys on and consumes animals; usually an animal
prey
an organism caught or hunted for food by another organism
producer
an organism that makes its own food from the environment; usually a green
plant
pulley
a type of simple machine; a circular lever, usually a wheel with a groove
where a rope can be placed and used to change the direction of a force
reflection
the bouncing off or turning back of light, sound, or heat from a surface
refraction
the bending of waves as they enter a different medium
renewable
resource
a resource that is replaced or restored, as it is used, by natural processes in a
reasonable amount of time
resource
any material that can be used to satisfy a need
scientific
method
a plan of inquiry that uses science process skills as tools to gather, organize,
analyze, and communicate information
sedimentary
rock
rock formed from layers of sediment that overlay and squeeze together or are
chemically combined
solar system
a star and all the planets and other bodies that orbit it; the region in space
where these bodies move
solid
having a definite shape and a definite volume; one of the fundamental states
of matter
solution
a mixture of two or more substances uniformly dispersed throughout a single
phase
star
a large, gaseous, self-luminous body held together by gravity and powered by
thermonuclear reactions
Sun
the closest star to Earth and the center of our solar system
system
a set of objects, organisms, or different parts acting to form a whole
tissue
similar cells acting to perform a specific function; four basic types of tissue
are muscle, connective, nerve, and epidermal
topography
the surface, shape, and composition of a land area
universe
the total sum of all matter and energy that exists
volcano
a vent or fissure in Earth’s surface through which magma and its associated
materials are expelled; generally a mountain-like structure
volume
a measure of the amount of space an object takes up; also the loudness of a
sound or signal
water cycle
the path water takes as it is being cycled through the environment, including
condensation, evaporation, and precipitation
weathering
the natural processes that break down and change rock into soil, sand, and
other materials; differs from erosion in that no transportation of those
materials takes place
wheel and axle
a type of simple machine; a circular frame or disk revolving around a central
axis
