Science
Vocabulary 1
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.
mass: the amount of matter an object contains
matter: a solid, liquid, or gas that possesses
inertia and is capable of occupying space
solid:
having a definite shape and a definite volume; one of the
fundamental
states of matter
liquid: one of the fundamental states of matter with
a definite volume but no definite shape
gas:
one of the fundamental states of matter in which the
molecules do
not have a fixed volume or shape
volume:
a measure of the amount of space an object takes up; also the loudness
of a sound or signal
Science
Vocabulary 2
system: a set of objects, organisms, or different
parts acting to form a whole
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
solar system: a star and all
the planets and other bodies that orbit it; the region in space where these bodies move
universe: the total sum of all matter and energy that
exists
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
constellation: a star pattern identified and named as a
definite group; usually
thought of as
forming certain shapes or figures in a specific
Science Vocabulary 3
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
evaporation: the process by which a liquid is converted
to its vapor phase by heating the liquid
solution: a mixture of two or more substances
uniformly dispersed throughout a single phase
investigation: a procedure that is carried out in order to observe a
response
caused by a stimulus; not a complete experiment
heat:
a form of energy resulting from the temperature difference
between a system and its surroundings
atmosphere: the layers of gas that surround Earth, other
planets, or stars
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
Science
Vocabulary 4
atom: the smallest unit of a chemical element that
can still retain the properties of that element
scientific method: a plan of inquiry that uses science process
skills as
tools to gather, organize, analyze, and communicate
information
planet:
a large body in space that orbits a star and does not produce
light of its own
microscopic: relating to an object too small to be visible without
the use of a microscope
gravity: the observed effect of the force of
gravitation
gravitation: a force of attraction between two masses
Science Vocabulary5
element: a substance that cannot be reduced to a
simpler substance by
chemical means
atom: the smallest unit of a chemical element
that can still retain the
properties of that element
energy:
a quantity that describes the capacity to do work; a source of usable
power.
energy transfer: a change of energy from one form to another (e.g.,
mechanical to electrical, solar to electrical)
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.
force:
a quality that tends to produce movement or acceleration of a body in the
direction of its application; a push or pull
friction:
a force that opposes the relative motion of two material surfaces in contact
with one another
Science
Vocabulary6
chemical
change: a reaction or a change in a
substance produced by chemical
means that
results in producing a different chemical.
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
change of
state: a physical change that
occurs when matter changes to another
state (i.e.
liquid, gas, or solid).
physical
change: reaction; a change in matter
from one form to another, without
forming new
substance.
resource: any material that can be used to satisfy a
need
renewable resource: a resource that is replaced or restored, as it is used, by
natural processes in a reasonable amount of time
pollution: any alteration of the natural environment
producing a condition
harmful to living
organisms; may occur naturally or as a result of
human activities
Science
Vocabulary7
carnivore:
an animal or plant that consumes or obtains nutrients from animals
community: all the populations of organisms
belonging to different species and
sharing the same
geographical area
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
food chain: transfer of energy through various stages as a result of
feeding patterns of a series of organisms
herbivore: an animal that feeds on plants
producer: an organism that makes its own food from the
environment; usually a
green plant
Science
Vocabulary8
deposition: layering matter in a natural process
earthquake: the shaking of the ground caused by a
sudden release of energy in
Earth's crust
erosion:
the wearing away of Earth's surface by the breakdown and transportation of rock
and soil
igneous rock: a type of rock that forms from molten or partly molten
material that cools and hardens
metamorphic rock: a type of rock that forms from existing rock because of
extreme changes caused by heat, pressure, or chemical environments
sedimentary rock: rock formed from layers of sediment that overlay and squeeze
together or are chemically combined
volcano:
a vent or fissure in Earth's surface through which magma and its associated
materials are expelled; generally a mountain-like structure
Science
Vocabulary 9
food web (food
cycle): the interconnected feeding
relationships in a food chain
found
in a particular place and time
habitat:
a place in an ecosystem where an organism normally lives
life cycle: the entire sequence of events in an organism's growth and development
organism: any
living plant, animal, or fungus that maintains various vital processes
necessary for life
population: a group of organisms of the same species living in a specific
geographical area
protist: unicellular organisms belonging to the
kingdom Protista
prey: an organism caught or hunted for
food by another organism
photosynthesis: a chemical process by which plants trap light energy to
convert carbon dioxide and water into carbohydrates (sugars)
Science
Vocabulary 10
wheel and axle: a type of simple machine; a circular frame or disk
revolving around a central axis
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
potential energy: the energy an object has because of its position or
structure; stored energy
magnetic: having
the property of attracting iron and certain other materials by virtue of a
surrounding field of force
lever: a
type of simple machine; consists of a rigid bar that pivots about a fulcrum,
used to transmit and enhance power or motion
kinetic
energy: the energy possessed by a
body because of its motion
fulcrum: the pivot point of a lever
Science Vocabulary 11
tissue:
similar cells acting to perform a specific function; four basic types of tissue
are muscle, connective, nerve, and epidermal
community: all the populations of organisms belonging
to different species and
sharing the same geographical area
predator:
an organism that preys on and consumes animals; usually an animal
organ:
a structure containing different tissues that are organized to carry out a
specific function of the body (e.g., heart, lungs, brain, etc.)
fossil: a
whole or part of a plant or animal that has been preserved in sedimentary rock
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
adaptation: a characteristic of an organism that
increases its chance of survival
in its environment
Science Vocabulary 12
conservation: controlled use and/or maintenance of natural resources;
various efforts to preserve or
protect natural resources
ecosystem:
an integrated unit of a biological community, its physical environment, and
interactions
nonrenewable resource: a resource that can only be
replenished over millions of years
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
topography:
the surface, shape, and composition of a land area
energy pyramid: a pyramidal diagram that compares the amount of energy
available at each position, or level, in the feeding order
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
Science Vocabulary 13
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
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
light: electromagnetic radiation that lies
within the visible range
reflection: the bouncing off or turning back of light, sound, or heat from a
surface
refraction: a change in the direction of a wave that occurs as it passes from
one medium to another of different density
water cycle: the path water takes as it is being cycled through the
environment, including condensation, evaporation, and precipitation
Science Vocabulary 14
density: A measure of the amount of matter that
exists in a given volume of material.
float
height: The height at which an
object will float in a liquid. Float height is directly related to the density
of the liquid.
mass: The measure of the amount of matter in
an object.
volume: A
measure of the amount of space an object occupies.
inverse
relationship: A relationship
between variables in which one increases as the other decreases.
Boyle’s law: At a
constant temperature, the pressure of a gas in a confined space increases as
the volume decreases.
Science
Vocabulary 15
evaporation: The conversion of a liquid to a gas or vapor.
filtrate: A substance in a solution that
passes through a filter.
heterogeneous: A mixture in which the components are
not evenly mixed, so that its properties are not the same throughout
homogeneous: A mixture in which the components are
evenly mixed, so that the mixture has the same properties throughout.
solute: The material dissolved in a solution.
solution: A mixture in which one substance is
dissolved in another.
A solution is a homogeneous mixture.
solvent: The substance in which the solute is
dissolved in a solution.
suspension: A heterogeneous mixture in which solid
particles are suspended in a liquid and may settle out.
Science Vocabulary 16
force: A push or pull on an object, measured
in newtons.
joule:
A unit of work; 1 joule of work is performed when a force of 1 newton is used
to move an object a distance of 1 meter.
newton: The
international unit of force.
work: The
transfer of energy resulting from a force acting to move an
object over a distance.
Work = Force × distance.
absorb: To take in.
circuit: The path comprised of wires and other
components through which electric current may flow.
oxidation: A chemical reaction that occurs when a
substance is exposed to oxygen
Science Vocabulary 17
friction:
A force that resists motion whenever the surfaces of two objects rub against each
other.
lubricant:
A substance used to reduce the friction between two solid surfaces.
atom:
The smallest part of an element that still retains all the properties of that
element.
cell:
The functional unit of living things.
covalent
bond: A type of bond between atoms in which one pair of electrons is shared.
electron:
A negatively charged particle orbiting the nucleus of an atom.
element: A pure substance that cannot be broken
down chemically into any other substances.
Science
Vocabulary 18
pulley:
A simple machine consisting of a wheel that rotates around a stationary
axle. The outer rim of the pulley is grooved to accommodate
a rope or chain.
proton:
A subatomic particle with a positive charge, located in the nucleus of an
atom
photosynthesis : The process by which plants use
chlorophyll to trap solar energy
to combine carbon
dioxide from the air with water from the soil to make their own food.
periodic table: A chart that presents an orderly
listing of all known elements
arranged from left to
right (groups) and top to bottom (periods) in order of increasing atomic number
solar
collector: A device used to collect solar energy and convert it to either
electricity or heat
solar energy: Energy from the sun
terrarium:
A container of land plants and/or animals
Science
Vocabulary 19
crescent: The first and last phase of the lunar
cycle, in which the Moon appears to have one very concave edge and one very
convex edge.
phase:
Any of the various stages of illumination of the Moon or a planet by the Sun.
gibbous:
The lunar phases between quarter Moon and full Moon in which the Moon
has convex edges.
full Moon: The lunar phase in which the entire
lighted surface of the Moon is
visible.
new
Moon: The lunar phase in which the lighted side of the Moon faces away from
Earth and so the Moon is not visible.
third quarter Moon: The lunar phase between full
Moon and new Moon when half
the
lighted portion of the Moon is visible.
first
quarter Moon: The lunar phase between new Moon and full Moon in which half
of the lighted portion of the Moon is
visible.
Science
Vocabulary 20
Orion: A constellation near
Gemini and Taurus.
mythology:
The study of myths.
Cassiopeia: The W-shaped
constellation in the Northern Hemisphere.
Cepheus:
A constellation near Cassiopeia and Draco
constellation: An area of the
sky containing stars that seem to outline a figure, as viewed from Earth.
horizon:
The apparent junction between Earth and the sky.
sunset:
The apparent descent of the Sun below the horizon; the time when the uppermost
portion of the Sun’s disk disappears below the horizon as a result of the
rotation of Earth.
Science
Vocabulary 21
landfill: An area of land that
has been excavated, filled with garbage or waste, and covered up with soil.
Landfills are usually monitored for the contamination of surrounding soil and
water.
reflect: To throw or bend back
from a surface.
subatomic particles:
The protons, neutrons, and electrons that make up an atom.
reactant: The starting material
in a chemical reaction; typically shown on the left side of a chemical
equation.
sunrise: The apparent rising of
the Sun above the horizon; the time when the uppermost portion of the Sun’s
disk appears above the horizon as a result of the rotation of Earth.
variable: The factor or condition
in a controlled experiment.
energy transfer: The movement of
energy from an energy source to an energy receiver.
filtrate: A substance in a
solution that passes through a filter.
Science Vocabulary 22
recycle: To use a material again
in the same or in a new way.
solute: The material dissolved
in a solution.
solar energy: Energy from the
sun.
newton: The international unit
of force.
independent variable:
In a controlled experiment, the variable that changes.
electron: A negatively charged
particle orbiting the nucleus of an atom.
absorb: To take in.
Science Vocabulary 23
phototropism: The growth of
plants toward light.
proton: A subatomic particle
with a positive charge, located in the nucleus of an atom.
solar collector: A device used to
collect solar energy and convert it to either electricity or heat.
suspension: A heterogeneous mixture
in which solid particles are suspended in a liquid and may settle out.
terrarium: A container of land
plants and/or animals.
acceleration: The rate of
change in speed and direction (velocity).
dependent variable:
In a controlled experiment, the variable that changes in response to changes in
the independent variable.
Science Vocabulary 24
xylem: A type of tissue in the
stems of plants that transports water and dissolved materials up from the roots
to the leaves.
phloem: A type of tissue in the
stems of plants that transports water and dissolved materials, like sugar,
between the leaves and roots.
stem: The part of a plant
that grows above ground, supports the leaves, and transports water and
dissolved materials between the roots and leaves.
third quarter Moon:
The lunar phase between full Moon and new Moon when half the lighted portion of
the Moon is visible.
evaporation: The conversion
of a liquid to a gas or vapor.
neutron: A subatomic particle
with no electric charge, located in the nucleus of an atom.
indirect sunlight:
Sunlight that reaches the surface of Earth at angles less than 45° to the
horizon.
Science Vocabulary 25
guard cells: In plants, the
two cells on either side of a stoma that function to open and close the stoma.
leaf: The broad, flat part of
a plant where photosynthesis takes place.
stoma (pl. stomata):
An opening in the leaf, similar to a pore in skin, that allows gases and water
to pass in and out.
transpiration: The loss of
water from the stomata in leaves.
covalent bond: A type of bond
between atoms in which one pair of electrons is shared.
energy level: One of a number
of electron clouds located at distinct distances from the nucleus of an atom.
hypothesis: An educated guess about
a scientific problem.
photosynthesis: The process by
which plants use chlorophyll to trap solar energy to combine carbon dioxide
from the air with water from the soil to make their own food.
