8th Grade
Science Vocabulary Review
The actual brightness
of a star
ABSOLUTE
MAGNITUDE
The transfer of energy
carried by light waves to
particles of matter
ABSORPTION
A characteristic that helps
an organism survive and
reproduce in its
environment
ADAPTATION
A large body of air that
has the same
temperature and
moisture throughout
AIR MASS
Alternate forms of a gene
that govern the same
characteristics
ALLELES
The maximum distance
the particles of a wave’s
medium vibrate from
their rest position
AMPLITUDE
How bright a light
appears to an observer
APPARENT MAGNITUDE
A measure of how much
surface an object has
AREA
The study of all physical
objects beyond Earth
ASTRONOMY
The smallest particle into
which an element can
be divided and still be
the same substance
ATOM
The weighted average of
the masses of all the
naturally occurring
isotopes of an element
ATOMIC MASS
The number of protons in
the nucleus of an atom
ATOMIC NUMBER
The state in which the
combined forces exerted
on an object add up to
zero
BALANCED
The theory that states
that the universe began
with a tremendous
explosion
BIG BANG THEORY
An object with more than
three solar masses
squeezed into a ball only
10 km across whose
gravity is so strong that
not even light can escape
BLACK HOLE
The movement of carbon
from the nonliving
environment into living
things and back
CARBON CYCLE
The largest population
that a given environment
can support over a long
period of time
CARRYING CAPACITY
The idea that all
geologic change
happens suddenly
CATASTROPHISM
The process by which
sediment is “glued”
together by minerals
dissolved in water
CEMENTATION
The force of attraction
that holds two atoms
together
CHEMICAL BOND
The joining of atoms to
form new substances
CHEMICAL BONDING
A change that occurs
when one or more
substances are changed
into entirely new
substances with
different properties
CHEMICAL CHANGE
A shorthand description
that uses chemical
formulas to describe a
chemical reaction
CHEMICAL EQUATION
A shorthand notation
that uses chemical
symbols and numbers
to represent a
substance
CHEMICAL FORMULA
The process by which
one or more
substances change to
produce one or more
different substances
CHEMICAL REACTION
A number placed in
front of a chemical
symbol or formula
COEFFICIENT
The process by which
soft sediment is
squeezed until it
hardens into rock
COMPACTION
A pure substance
composed of two or
more elements that
are chemically
combined
COMPOUND
The theory that
continents can drift
apart from one
another and have done
so in the past
CONTINENTAL DRIFT
The process by which
cooler material sinks
while warmer
material rises because
of a change in density
CONVECTION
The boundary between
two colliding tectonic
plates
CONVERGENT
BOUNDARY
A bond that results
from the attraction
between the nuclei of
atoms where the
electrons are shared
by the atoms
COVALENT BOND
Any pieces of
information gathered
through
experimentation
DATA
The process of clearing
forests
DEFORESTATION
To change shape
because of the action
of geologic processes
DEFORM
The amount of matter
in a given space or
volume
DENSITY
The boundary between
two tectonic plates
that are moving away
from each other; rift
zone
DIVERGENT BOUNDARY
The trait observed
when at least one
dominant allele for a
characteristic is
inherited
DOMINANT TRAIT
The apparent change in
frequency of a sound
caused by the motion
of either the listener or
the source of the
sound
DOPPLER EFFECT
A community of
organisms and their
nonliving
environment
ECOSYSTEM
The entire range of
electromagnetic waves,
all the wavelengths of
electromagnetic
radiation
ELECTROMAGNETIC
SPECTRUM
A wave that can travel
through space and
matter and consists of
vibrating electric and
magnetic fields
ELECTROMAGNETIC
WAVE
A negatively charged
subatomic particle that
is found in all atoms
ELECTRONS
A region inside an
atom where electrons
are likely to be found
ELECTRON CLOUD
A pure substance that
cannot be separated
into simpler substances
by physical or chemical
means
ELEMENT
A spherical or
elongated galaxy with
a bright center and
very little dust and
gas
ELIPTICAL GALAXY
A periodic change in the
location of warm and
cool surface waters in
the Pacific Ocean
EL NINO
The term used to
describe a physical or
chemical change in
which energy is
absorbed
ENDOTHERMIC
Regions around the
nucleus of an atom
where electrons may
be found
ENERGY LEVELS
The process by which
wind, water, ice, and
gravity remove and
transport material
from one place to
another
EROSION
The term used to
describe a physical or
chemical change in
which energy is given
off
EXOTHERMIC
The type of strain that
occurs when rocks
break because of
stress
FAULTING
A messaging system
that the body uses to
maintain equilibrium
FEEDBACK MECHANISM
The type of strain that
occurs when rocks
bend because of
stress
FOLDING
The number of waves
made in a given
amount of time
FREQUENCY
The area where two
different air masses
meet
FRONT
A large grouping of stars
in space
GALAXY
The inherited
combination of alleles
GENOTYPE
The scientific study of
the Earth’s history
GEOLOGY
Each vertical column
of elements (from top
to bottom) on the
periodic table
GROUP
The transfer of energy
between objects that
are at different
temperatures
HEAT
Hertzsprung-Russell
diagram showing the
relationship between a
star’s surface
temperature and
absolute magnitude
H-R DIAGRAM
A large, spinning
tropical weather
system with wind
speeds of at least 119
km/h
HURRICANE
A possible explanation
or answer to a
question
HYPOTHESIS
Rock that forms when
hot, liquid rock cools
and hardens
IGNEOUS ROCK
The force of attraction
between oppositely
charged ions
IONIC BOND
A galaxy that does not
fit into any other
category
IRREGULAR GALAXY
The energy of motion
KINETIC ENERGY
Magma that reaches the
Earth’s surface
LAVA
The law that states
that mass is neither
created nor destroyed
in ordinary chemical
and physical changes
LAW OF CONSERVATION
OF MASS
A UNIT OF LENGTH
EQUAL TO THE
DISTANCE THAT LIGHT
TRAVELS THROUGH
SPACE IN 1 YEAR
LIGHT-YEAR
Literally, the “rock
sphere” – the cool, rigid,
outermost layer of the
Earth that is divided into
enormouse pieces called
tectonic plates
LITHOSPHERE
The orbit of the moon
around the Earth,
during which all of the
lunar phases occur
LUNAR CYCLE
The different
appearances of the
moon throughout the
month
LUNAR PHASES
The diagonal pattern of
stars on the H-R
diagram; where stars
spend most of their
time
MAIN SEQUENCE
The solid layer of the
Earth between the
crust and the core;
made of dense iron
rich minerals
MANTLE
The amount of matter
that something is made
of
MASS
The total number of
protons and neutrons
in an atom
MASS NUMBER
Anything that has
volume and mass
MATTER
A substance through
which a wave can
travel
MEDIUM
Rock that forms when
existing rock is heated
and squeezed deep
inside the Earth
METAMORPHIC ROCK
EM waves that are
between radio waves
and infrared waves in
the electromagnetic
spectrum
MICROWAVES
Underwater mountain
chain that forms on the
ocean floor where
tectonic plates pull
apart
MID-OCEAN RANGE
A naturally formed
inorganic rock solid
that has a repeating
three-dimensional
structure
MINERAL
A representation of an
object or system
MODEL
A neutral group of
atoms held together
by covalent bands
MOLECULE
The process by which
organisms with certain
traits survive and
reproduce at a higher
rate then organisms
without these traits
NATURAL SELECTION
Tides with the smallest
daily tidal range that
occur during the first
and third quarters of
the moon
NEAP TIDES
A star in which nearly all
the particles have
become neutrons
NEBULA
A subatomic particle
of the nucleus of an
atom that has no
charge
NEUTRON
A large cloud of dust
and gas in interstellar
space
NEBULA
The movement of
nitrogen from the
nonliving
environment into
living things and back
NITROGEN CYCLE
The tiny, very dense,
positively charged
region in the center of
an atom
NUCLEUS
A streamlike
movement of water in
the ocean
OCEAN CURRENT
A symbiotic association
in which one organism
benefits while the
other is harmed
Parasitism
Each horizontal row of
elements (from left to
right) on the periodic
table
PERIOD
An arrangement of the
elements according to
their atomic numbers
PERIODIC TABLE OF THE
ELEMENTS
An organism’s
appearance
PHENOTYPE
The theory that the
lithosphere is divided
into tectonic plates that
move around on top of
the asthenosphere
PLATE TECTONICS
Water, in a solid or
liquid form, that falls
from the air to Earth
PRECIPITATION
A substance formed
from a chemical
reaction
PRODUCT
A positively charged
subatomic particle of
the nucleus of an
atom
PROTON
EM waves with long
wavelengths and low
frequencies
RADIO WAVES
A starting material in a
chemical reaction
REACTANT
A trait that is apparent
only when two
recessive alleles for the
same characteristic are
inherited
RECESSIVE TRAIT
The process of
breaking down trash
and using the
materials again
RECYCLING
The bouncing back of a
wave after the wave
hits a barrier
REFLECTION
A natural resource that
can be used over and
over or that has an
unlimited supply
RENEWABLE RESOURCE
The continual process
by which new rock is
formed from old rock
ROCK CYCLE
The ways in which
scientists answer
questions and solve
problems
SCIENTIFIC METHODS
The process by which new
oceanic lithosphere
forms at mid-ocean
ridges as tectonic plates
are pulled away from
each other
SEA-FLOOR SPREADING
Rock that forms when
pieces of rocks or
minerals are “glued”
together
SEDIMENTARY ROCK
The amount of energy
needed to change the
temperature of 1 kg or
a substance by 1ºC
SPECIFIC HEAT CAPACITY
The rainbow of colors
produced when white
light passes through a
prism or spectrograph
SPECTRUM
A galaxy with a bulge in
the center and very
distinctive spiral arms
SPIRAL GALAXY
Tides that have the
largest daily tidal
range and occur
during the new and
full moons
SPRING TIDE
The amount of force per
unit area that is put on
a rock
STRESS
The region where
oceanic lithosphere
sinks down into the
asthenosphere at a
convergent boundary
SUBDUCTION ZONE
A close, long-term
association between
two or more species
SYMBIOSIS
A number written
below and to the right
of a chemical symbol
in a formula
SUBSCRIPT
Huge pieces of the
lithosphere that move
around on top of the
asthenosphere
TECTONIC PLATES
A measure of how hot
(or cold) something is
TEMPERATURE
A unifying explanation for
a broad range of
hypotheses and
observations that have
been supported by
testing
THEORY
Daily changes in the
level of ocean water
TIDES
The boundary between
two tectonic plates
that are sliding past
each other
TRANSFORM BOUNDARY
The lowest point of a
wave
TROUGH
EM waves that are
between visible light
and X rays in the
electromagnetic
spectrum
ULTRAVIOLET WAVES
The state in which the
combined forces
exerted on an object
do not add up to zero
UNBALANCED
All space and the matter
space contains
UNIVERSE
The rising of regions of
Earth’s crust to higher
elevations
UPLIFT
The electrons in the
outermost energy level
of an atom
VALENCE ELECTRONS
A process in which
cold, nutrient-rich
water from the deep
ocean rises to the
surface and replaces
warm surface water
UPWELLING
The movement of water
through the
atmosphere, the
ground, bodies of
water, and living things
WATER CYCLE
A disturbance that
transmits energy
through matter or
space
WAVE
The distance between
any two corresponding
points that are
adjacent on a wave
WAVELENGTH
The condition of the
atmosphere at a
certain time and place
WEATHER
The time required for
the Earth to revolve
once around the sun
YEAR
The tendency of all
objects to resist any
change in motion
INERTIA
The bending of a wave
as the wave passes at
an angle
REFRACTION
A wave that travels
only through matter
by creating vibrations
in a medium
MECHANICAL WAVES
Properties that DO NOT
change the chemical
nature of matter
PHYSICAL PROPERTIES
Elements that are
grouped together
based on their
chemical properties
and reactivity
FAMILIES / GROUPS
The passing of light
through matter
TRANSMITTED
Push or Pull –
measured in (N)
Newtons
FORCE
The highest point on a
wave
CREST
An abbreviation of a
chemical element
using one or two
letters
CHEMICAL SYMBOL
The force of attraction
between two objects
GRAVITY
Causes a change in the
speed or direction of
an object’s motion
UNBALANCED FORCES
The very narrow range of
wavelengths and
frequencies in the
electromagnetic
spectrum that humans
can see
VISIBLE LIGHT
Properties that DO
change the chemical
nature of matter
CHEMICAL PROPERTIES
The transfer of energy
through matter or space
as electromagnetic
waves, such as visible
light and infrared waves
RADIATION
A star in which nearly
all of the particles
have become
neutrons
NEUTRON STAR
The transfer of energy
from one substance to
another through direct
contact
CONDUCTION
The gel-like fluid
mixture inside a cell
CYTOPLASM
Usually found in plant
cells where
photosynthesis takes
place
CHLOROPLASTS
The part of the
microscope that holds
the slide in place on
the stage
STAGE CLIPS
The part of the
microscope that
supports the slide and
allows light to come
through
STAGE
The part of the
microscope that you
put your eye on to
look at an organism
EYEPIECE
The part of the
microscope that
supports the eyepiece
and maintains the
correct distance from the
eyepiece and the
objectives
BODY TUBE
The part of the cell
that destroys worn
out or damaged
organelles and gets
rid of waste material
LYSOSOME
The part of the cell that
burns food molecules
to release energy
MITOCHONDRIA
A group of organisms
that lack a cell
nucleus. Single-celled
organisms like
bacteria
PROKARYOTES
The organelle that
packages and
transports material out
of the cells
GOLGI BODIES
The outermost
structure of a plant
cell that provides
strength and support
CELL WALL
Large vesicles found in
plant cells that store
water and other liquids
VACUOLES
The outer membrane
of a cell that controls
movement in and out
of the cell
CELL MEMBRANE
A fault in which the
hanging wall moves
down because of
tension
NORMAL FAULT
Hot, liquid rock
material
MAGMA
A fault in which the
hanging wall moves up
because of
compression
REVERSE FAULT
The presence of
harmful or unwanted
levels of substances in
the environment
POLLUTION
A fault in which the
plates move
horizontally past each
other because of
shearing
STRIKE-SLIP FAULT
A force that causes
rocks to be pulled
apart
TENSION
The circular motion of
liquids or gases caused
by density differences
that result from
temperature differences
CONVECTION CURRENTS
A force that causes
rocks to slide
horizontally past each
other
SHEARING
The process by which
sediments are
deposited / dropped in
a new location
DEPOSITION
The type of stress in
which an object is
squeezed, as when
two plates collide
COMPRESSION
The process by which
water, ice, wind, and
heat act to break down
rocks
WEATHERING
The organelle that
makes proteins
RIBOSOME