Physical Science Final Defns

Front 1

Acceleration

Back 1

The time rate of change of an object's velocity

Front 2

Air Mass

Back 2

A large body of air with relatively uniform pressure, temperature, and humidity

Front 3

Aphelion

Back 3

The point at which the earth is farthest from the sun

Front 4

Atmosphere

Back 4

The mass of air surrounding a planet

Front 5

Atom

Back 5

The smallest stable unit of matter in Creation

Front 6

Atomic Number

Back 6

The number of protons in an atom

Front 7

Beta Decay

Back 7

The process by which a neutron turns into a proton by emission of an electron

Front 8

Centripetal Force

Back 8

Force that is always directed perpendicular to the velocity of an object

Front 9

Charging by Conduction

Back 9

Charging an object by allowing it to come into contact with an object which already has an electrical charge

Front 10

Charging by Induction

Back 10

Charging an object by forcing dome of the charges to leave the object

Front 11

Cohesion

Back 11

The phenomenon that occurs when individual molecules are so strongly attracted to each other that they tend to stay together, even when exposed to tension

Front 12

Concentration

Back 12

The quantity of a substance within a certain volume of space

Front 13

Condensation

Back 13

The process by which water vapor turns into liquid water

Front 14

Critical Mass

Back 14

The amount of isotope necessary to cause a chair reaction

Front 15

Earth's Crust

Back 15

Earth's outermost layer of rock

Front 16

Earthquake

Back 16

A trembling or shaking of earth as a result of rock masses suddenly moving along a fault

Front 17

Electrolysis

Back 17

Using electricity to break a molecule down into it's constituent elements

Front 18

Element

Back 18

A collection of atoms that all have the same number of protons

Front 19

Epicenter

Back 19

The point on the surface of the earth directly above an earthquake's focus

Front 20

Focus

Back 20

The point along a fault when an earthquake begins

Front 21

Free Fall

Back 21

The state of an object that is falling towards the earth with nothing inhibiting its fall

Front 22

Friction

Back 22

A force resulting from the contact of two surfaces. This force opposes motion

Front 23

Galaxy

Back 23

A massive ensemble of hundreds of millions of stars, all interacting through the gravitational force, orbiting around a common center

Front 24

Greenhouse Effect

Back 24

The process by which certain gases trap heat that would otherwise escape the earth and radiate into space

Front 25

Half-Life

Back 25

The time it takes for half of the original sample of radioactive isotope to decay

Front 26

Humidity

Back 26

The moisture content of air

Front 27

Hydrosphere

Back 27

The mass of water on a planet

Front 28

Igneous Rock

Back 28

Rock that forms from molten rock

Front 29

Isotopes

Back 29

Two or more atoms that have the same number of protons but different numbers of neutrons

Front 30

Jet Streams

Back 30

Narrow bands of high-speed winds that circle the earth, blowing from west to east

Front 31

Kinetic Friction

Back 31

The friction that exists between surfaces which at least one of those surfaces is moving relative to the other

Front 32

Lines of Latitude

Back 32

Imaginary lines that run east and west across the earth

Front 33

Lines of Longitude

Back 33

Imaginary lines that run north and south across the earth

Front 34

Mass Number

Back 34

The sum of the number of neutrons and protons in the nucleus of an atom

Front 35

Molecule

Back 35

Two or more atoms linked together to make a substance with unique properties

Front 36

Nuclear Fission

Back 36

The process by which a large nucleus is split into two smaller nuclei

Front 37

Nuclear Fusion

Back 37

The process by which two or more small nuclei fuse to make a bigger nucleus

Front 38

Nucleus

Back 38

The center of an atom, containing the protons and neutrons

Front 39

Perihelion

Back 39

The point at which the earth is closet to the sun

Front 40

Pitch

Back 40

The highness or lowness of a sound

Front 41

Polar Molecule

Back 41

A molecule that has slight positive and negative charges due to an imbalance in the way electrons are shared

Front 42

Precipitation

Back 42

Water falling from the atmosphere as rain, snow, sleet, or hail

Front 43

Reference Point

Back 43

A point against which position is measured

Front 44

Salinity

Back 44

A measure of the quantity of dissolved salt in water

Front 45

Sediment

Back 45

A deposit of sand and mineral fragments, usually laid down by water

Front 46

Solute

Back 46

A substance that is dissolved in a solvent

Front 47

Solvent

Back 47

A liquid substance capable of dissolving other substances

Front 48

Sonic Boom

Back 48

The sound produced as a result of an object traveling at or above Mach 1

Front 49

Star Magnitude

Back 49

The brightness of a star on a scale of -8 to +17

Front 50

Static Friction

Back 50

The friction that exists between surfaces when neither surface is moving relative to the other

Front 51

Temperature

Back 51

A measure of the energy of motion in a substance's molecules

Front 52

Updraft

Back 52

A current of rising air

Front 53

Vector Quantity

Back 53

A physical measurement that contains directional information

Front 54

Water Table

Back 54

The imaginary line between the water-saturated soil and the soil not saturated with water