8th grade science vocab terms

Question 1

opposite poles of a magnet do this

Answer 1

attract

Question 2

the range of wavelengths or frequencies over which electromagnetic radiation extends (includes gamma, x-ray, UV, visible light, infrared, microwave, and radio waves)

Answer 2

Electromagnetic spectrum

Question 3

analyzed preserved remains, traces of animals & plants, and microorganisms to reconstruct the history of life on Earth

Answer 3

fossil record

Question 4

generated when a bar magnet is moved through a wire coil

Answer 4

electric current

Question 5

uses curved mirrors, largest optical telescopes in the world

Answer 5

reflecting telescope

Question 6

empty space that only electromagnetic waves can travel through

Answer 6

vacuum

Question 7

part of the earth’s crust that is thick but not as dense as oceanic crust

Answer 7

continental crust

Question 8

formed when oceanic crust subducts under continental crust at subduction zones (Convergence-Oceanic subduction)

Answer 8

volcanic mountain range

Question 9

also known as artificial selection, is a process used by humans to develop new organisms with desirable characteristics.

Answer 9

selective breeding

Question 10

change in direction of waves that occurs when waves travel from one medium to another.

Answer 10

refraction

Question 11

formed in the ocean when magma rises up, erupts, cools and solidifies and pushes the sea-floor outwards.

Answer 11

mid ocean ridge

Question 12

Long, narrow ditches in the Earth’s crust when 2 or more oceanic plates converge and one subducts under the other.

Answer 12

trench

Question 13

a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity.

Answer 13

sea floor spreading

Question 14

waves that don’t require a medium.

Answer 14

electromagnetic wave

Question 15

bouncing back of waves.

Answer 15

reflection

Question 16

thinnest layer of the Earth.

Answer 16

crust

Question 17

68% of Earth’s mass, movement in this layer causes the movement of the continents (convection currents)

Answer 17

mantle

Question 18

uses mechanical energy to produce electricity.

Answer 18

generator

Question 19

type of mechanical wave where the energy runs at right angles (perpendicular) to the wave.

Answer 19

transverse wave

Question 20

during the first and third quarters of the Moon, Moon and Sun are at right angles to each other.

Answer 20

neap tide

Question 21

occurs whenever there is a full or new moon, Sun and Moon must either be in a straight line on the same side of Earth, or they must be on opposite sides of Earth, gravity causes very high and very low tides

Answer 21

spring tide

Question 22

largely metallic and mainly iron, the outer core is liquid and responsible for generating the Earth’s magnetic field

Answer 22

outer core

Question 23

when one plate dives under another plate due to it being more dense.

Answer 23

subduction

Question 24

most dense layer of Earth, SOLID DUE TO IMMENSE PRESSURE. This is also why it is the hottest layer.

Answer 24

inner core

Question 25

occurs when two plates collide together. Form mountains, island arcs, volcanos. and ocean trenches.

Answer 25

convergent plate boundary

Question 26

occurs when an object moves towards the observer

Answer 26

blueshift

Question 27

plates that are moving apart. Form mid ocean ridges and continental drift zones

Answer 27

divergent plate boundary

Question 28

For every action there is an equal but opposite reaction

Answer 28

Newton's 3rd law

Question 29

force that opposes motion

Answer 29

friction

Question 30

Structures that have “lost” their original use

Answer 30

Vestigial structure

Question 31

simply a coil of wire wrapped around an iron core connected to an electric current producing a magnetic field.

Answer 31

electromagnet

Question 32

Two ways to increase strength of electromagnet

Answer 32

1) increase current 2) increase number of coils

Question 33

Age of a fossil by comparing it to the fossils around it, generally which is older and which is younger- no exact numbers.

Answer 33

Relative age

Question 34

similar structure, different function/job

Answer 34

Homologous structure

Question 35

different structure, similar function/job

Answer 35

analogous structure

Question 36

also known as selective breeding, is a process used by humans to develop new organisms with desirable characteristics.

Answer 36

artificial selection

Question 37

uses refracting lenses to see things within our solar system.

Answer 37

refracting telescope

Question 38

one complete wave cycle; usually measured crest to crest or trough to trough

Answer 38

wavelength

Question 39

any characteristic or trait that allows an organism to survive

Answer 39

adaptation

Question 40

lowest point of a wave

Answer 40

trough

Question 41

highest part of a wave

Answer 41

crest

Question 42

proposed the theory of Continental Drift which became the basis for today’s modern plate tectonic theory.

Answer 42

Alfred Wegener

Question 43

a break in the rocks that make up the Earth's crust, along which rocks on either side have moved past each other.

Answer 43

fault

Question 44

when plates slide past each other.

Answer 44

transform plate boundary

Question 45

rides on plates and is more dense but less thick than continental crust.

Answer 45

oceanic crust

Question 46

speed and direction

Answer 46

velocity

Question 47

can be moved through a wire coil to induce an electric current

Answer 47

bar magnet

Question 48

Proposed the process of natural selection based on observations made during his travels.

Answer 48

Charles Darwin

Question 49

Describes how force and mass affects acceleration (f=ma)

Answer 49

Newton's 2nd law of motion

Question 50

below lithosphere and part of upper mantle, behaves plastically and flexible, hot solid and malleable

Answer 50

Asthenosphere

Question 51

part of the crust and uppermost mantle, floats on top of the asthenosphere, brittle and rigid

Answer 51

Lithosphere

Question 52

process by which living things with beneficial traits produce more offspring, so their traits become more common over time.

Answer 52

Natural Selection

Question 53

type of mechanical wave in which the energy flows parallel to the wave. (rarefaction, compression)

Answer 53

Longitudinal wave

Question 54

occurs when waves bend around small obstacles or openings.

Answer 54

Diffraction

Question 55

when water reaches the lowest point (twice a day)

Answer 55

low tide

Question 56

when water reaches the highest point (twice a day)

Answer 56

high tide

Question 57

An unmanned spacecraft designed to explore the solar system & transmit data back to earth, uses radio waves

Answer 57

space probe

Question 58

used for navigation systems, such as the Global Positioning System (GPS)

Answer 58

navigational satellites

Question 59

receive and send signals for telephone, television, or other types of communications.

Answer 59

communication satellites

Question 60

Take pictures of Earth’s surface for military or scientific purposes.

Answer 60

imaging satellites

Question 61

body of matter

Answer 61

medium

Question 62

waves that require a medium to travel in. (sound waves, water waves, etc.)

Answer 62

mechanical wave

Question 63

rocks that have been changed due to temperature and pressure increases.

Answer 63

metamorphic

Question 64

(primary) First to be detected by seismometer, Longitudinal motion, refract/bend when changing earth’s layers- faster in denser material, FASTEST MOVING WAVES, Travel fastest through SOLID inner core

Answer 64

P-wave

Question 65

(secondary) Half as fast a P-waves, Arrive second at seismographs, Transverse motion, Can only travel through solids

Answer 65

S-wave

Question 66

distance of a wave measured from the equilibrium point (how high or low the wave goes)

Answer 66

amplitude

Question 67

Number of vibrations per unit time, measured in Hertz (Hz), determines pitch in sound waves, determines color in light waves.

Answer 67

frequency

Question 68

Device used to separate white light from a star into a very wide spectrum of color, Gives information about wavelength, frequency, & energy, HELPS DETERMINE CHEMICAL COMPOSITION OF STARS

Answer 68

spectroscope

Question 69

when energy of a wave is not transferred though or reflected by the medium.

Answer 69

absorption

Question 70

when waves pass through a point or a medium.

Answer 70

transmission

Question 71

this is what like poles on a magnet do.

Answer 71

repel

Question 72

takes electrical energy and converts it to mechanical energy/motion.

Answer 72

motor

Question 73

amount of matter in an object

Answer 73

mass

Question 74

is formed through the cooling and solidification of magma or lava. Can be “intrusive”(cools inside Earth) OR “extrusive” (outside)

Answer 74

igneous rock

Question 75

physical traits or characteristics

Answer 75

phenotype

Question 76

rocks formed by deposition and cementation in layers. Most fossils are found in this type of rock.

Answer 76

sedimentary

Question 77

force of gravity acting on an object.

Answer 77

weight

Question 78

is the theory that the Earth's continents have moved over geologic time relative to each other, thus appearing to have "drifted" across the ocean bed.

Answer 78

continental drift

Question 79

Uses radioactive materials to determine the exact ages of rocks & fossils in each layer (radiometric dating)

Answer 79

absolute

Question 80

highest point of a wave

Answer 80

crest

Question 81

change in speed over time

Answer 81

acceleration

Question 82

An object at rest stays at rest and an object in motion stays in motion UNLESS acted on by an outside force.

Answer 82

Newton's 1st law

Question 83

occurs when an object is moving away from an observer.

Answer 83

Redshift