8th Grade

Science Vocabulary Review

The actual brightness of a star

ABSOLUTEMAGNITUDE

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