Science Eight Grade Final

Front 1

matter

Back 1

anything that has mass and takes up space. (Heat, light are not matter)

Front 2

law of conservation of matter

Back 2

matter cannot be created or destroyed, just change states. Antoine Lavoisier introduced it.

Front 3

the atom

Back 3

a small particle that makes up most of the matter in the world. The nucleus is in the center and is composed of protons and neutrons; the electrons are along the energy levels outside the nucleus.

Front 4

electron cloud

Back 4

a model that shows that electrons are so small and fast that they move in a cloud

Front 5

element

Back 5

is matter made up of only one kind of atom, there are 115 elements. 90 are naturally occurring, the others aren’t

Front 6

periodic table

Back 6

• The periodic table has all of the elements. The atoms all have a number on the top that is called the atomic number and it tells the amount of protons in the nucleus of each atom of an element. The mass number is the sum of an atoms protons and neutrons. The atomic mass is the average mass for the isotopes of an element.

Front 7

isotopes

Back 7

Isotopes of an element are atoms of the same elements that have different numbers of neutrons

Front 8

atomic number

Back 8

The atoms all have a number on the top that is called the atomic number and it tells the amount of protons in the nucleus of each atom of an element.

Front 9

mass number

Back 9

The mass number is the sum of an atoms protons and neutrons

Front 10

atomic mass

Back 10

The atomic mass is the average mass for the isotopes of an element.

Front 11

compound

Back 11

Compounds are made up of two or more elements and are chemically combined and proportions can’t be changed

Front 12

mixture

Back 12

Mixtures are not chemically combined and proportion can be changed

Front 13

heterogeneous mixture

Back 13

In heterogeneous mixtures, you can see the different parts

Front 14

homogeneous mixture

Back 14

Homogeneous mixtures look the same throughout

Front 15

metals

Back 15

shiny, metallic luster, good conductors of heat and electricity, malleable (can be shaped), ductile (can be drawn into wires without breaking)
except mercury metals are solids at room temperature

Front 16

nonmetals

Back 16

dull, most are poor conductors of heat and electricity, brittle
most are gases are gasses at room temperature
97% of human body is made up of nonmetals

Front 17

metalloids

Back 17

has characteristics of metals and nonmetals
all solids at room temperature, some shiny, many are conductors

Front 18

solid

Back 18

Solids have definite shape and volume because particles are packed closely and vibrate in place

Front 19

liquid

Back 19

Liquids have a definite volume, but not a definite shape

Front 20

gas

Back 20

Gas does not have definite volume or shape, gas particles spread out evenly as far as possible

Front 21

states of matter

Back 21

solid, liquid, gas, plasma

Front 22

plasma

Back 22

occurs only at very high temperatures and is not common on earth

Front 23

crystalline solids

Back 23

Crystalline solids are particles arranged in a repeating, three-dimensional pattern

Front 24

amorphous solids

Back 24

Amorphous solids have random arrangement of particles

Front 25

viscosity

Back 25

Viscosity is a liquid’s resistance to flow and increases when particles are more attracted to each other

Front 26

surface tension

Back 26

uneven forces acting on the particles of a liquid’s surface

Front 27

heat

Back 27

the movement of thermal energy from a substance with a higher temperature to one with a lower temperature.

Front 28

thermal energy

Back 28

Thermal energy is the total energy in a sample of matter

Front 29

temperature

Back 29

Temperature is the average energy in a sample of matter

Front 30

melting

Back 30

Solid to liquid

Front 31

freezing

Back 31

Liquid to Solid

Front 32

condensation

Back 32

Gas to Liquid

Front 33

vaporization

Back 33

evaporation and boiling
Liquid to gas

Front 34

sublimation

Back 34

Solid to Gas

Front 35

deposition

Back 35

Gas to Solid

Front 36

evaporation

Back 36

Evaporation is vaporization that occurs at the surface of the liquid; molecules must be at or near the surface of a liquid and at the right speed to evaporate

Front 37

boiling

Back 37

Boiling is vaporization that occurs below the liquid’s surface at its boiling point

Front 38

pressure

Back 38

is the force exerted on a surface divided by the total area over which the force is exerted
P= F/A
SI unit- pascal (Pa)
less area more pressure
more area less pressure
more force more pressure
less force less pressure

Front 39

buoyant force

Back 39

• Buoyant Force is an upward force on an object immersed in water. If the buoyant force is greater than the force that the object is giving off on the water, it will float and vice-versa

Front 40

archimedes' principle

Back 40

Archimedes’ Principle states that buoyant force in an object is equal to the weight of the fluid displaced by the object

Front 41

pascal's principle

Back 41

Pascals Principles states that when a force is applied to a confined fluid, the pressure is transmitted equally throughout. It is used in hydraulics to lift heavy objects and in force pumps

Front 42

density

Back 42

Density is mass divided by volume. It is the amount of mass in a specific volume. An object will float in a fluid that is more dense than it
g/cm3
when you find the density of something you know what the thing is because no matter how big or small something is it always will have the same density

Front 43

physical properties

Back 43

Physical properties are any characteristics of matter that can be observed without changing the identity of the material. Physical properties include color, shape, smell, taste, etc

Front 44

chemical properties

Back 44

Chemical properties are characteristics that allow something to turn into something new. Chemical properties include flammability, toxicity, and reactivity with oxygen

Front 45

size dependent property

Back 45

size-dependent property is a physical property that changes with size. Examples are length, width, height, mass, etc

Front 46

size independent property

Back 46

A size independent property does not change with size. Examples are color, state, and density

Front 47

acids

Back 47

Acids are substances that have a pH of 0 to 7. They have a sharp smell and sour taste. They have H+ ions. They corrode metal. Examples are oranges, lemons, sodas, battery acid

Front 48

bases

Back 48

Bases have pH levels that are higher than 7. They are bitter and slippery. They have OH- ions. They are often used as cleaners. Examples of bases are soap, shampoo, ammonia, and milk of magnesia

Front 49

salt

Back 49

Salts are made up of metals and nonmetals that are formed when acids and bases react. When HCl and NaOH react we get NaCl (table salt) and H2O (water)

Front 50

physical change

Back 50

Physical changes are changes in shape, size, state, or form where the identity of the matter stays the same

Front 51

chemical change

Back 51

Chemical changes are changes that change the identity of the matter

Front 52

signs of a chemical change

Back 52

• Signs of a chemical change include release or absorption of energy in the form of light, heat, or sound, formation of gas or solid not from a change of state

Front 53

newton's first law

Back 53

if the net force acting on an object is zero, the object remains at rest, or if the object is already moving, it continues moving in a straight line a constant speed, except when an outside force interferes

Front 54

newton's second law

Back 54

Acceleration= Net force over the mass of an object A=Fnet/m Acceleration is inversely proportionate with mass, which means that the smaller the mass, the more acceleration vice-versa

Front 55

newtons third law

Back 55

For every action, there is an equal and opposite reaction

Front 56

renewable energy

Back 56

Renewable energy sources are constantly replenished
Plants, trees, etc. are renewable

Front 57

nonrenewable energy

Back 57

Non-renewable energy sources are used much quicker than they are replenished
Fossil fuels are non-renewable

Front 58

inexhaustible energy

Back 58

Inexhaustible energy sources cannot be used up by humans
Solar power, wind power, hydroelectricity, etc. are inexhaustible

Front 59

kinetic energy

Back 59

Kinetic energy is the energy of motion
SI unit- Jules (J)
1/2mv2

Front 60

potential energy

Back 60

Potential energy is stored energy based on position. There are 3 types of this energy: Elastic, Chemical, and gravitational
SI unit- Jules (J)
mgh
massXgravity(9.8)Xheight
weight is mass times gravity or mg

Front 61

law of conservation of energy

Back 61

The Law of Conservation of Energy states that energy is not created or destroyed, but changes forms

Front 62

scientific theory

Back 62

an attempted explanation for repeatedly observed patterns in the natural world

Front 63

scientific law

Back 63

a rule that describes a pattern in nature

Front 64

three branches of science

Back 64

life science- living things and how they interact
earth science- earth and space systems
physical science- matter and energy (chemistry and physics)

Front 65

technology

Back 65

the practical use of science

Front 66

scientific method

Back 66

includes observing, questioning, and researching; forming a hypothesis; predicting an outcome; investigating; analyzing; forming conclusion, communicating findings; and repeating the process

Front 67

inference or infer

Back 67

conclusions based on observations

Front 68

independent or manipulative variable

Back 68

the variable that is changed in an experiment

Front 69

dependent or responding variable

Back 69

the variable that changes as a result of a change in the independent variable

Front 70

graphing variables

Back 70

dry mix
dependent responding y axis
manipulative independent x axis

Front 71

analyzing data

Back 71

looking over your data and organizing it

Front 72

control

Back 72

the part of the experiment that is used as a comparison

Front 73

constant

Back 73

variables that remain unchanged

Front 74

precision

Back 74

a description of how close measurements are to each other

Front 75

accuracy

Back 75

when you compare a measurement to the real, actual, or accepted value

Front 76

SI units

Back 76

length-m meters
mass-kg kilograms
temperature-K kelvin
time-s seconds
volume-m3 meters cubed and L liters
weight/force- newtons

Front 77

SI unit conversion

Back 77

milli- 0.001
centi- 0.01
deci- 0.1
base- 1
deka- 10
hecto- 100
kilo- 1,000

Front 78

volume by immersion

Back 78

finding the volume of something irregular by starting with a shown volume of water and drop or immerse the object, the increase in the volume of the water is equal to the volume of the object

Front 79

line graph

Back 79

shows the relationship between two variables
uses numbers only

Front 80

bar graph

Back 80

uses rectangular blocks, or bars, of varying sizes to shows the relationships among variables

Front 81

circle graph

Back 81

show the parts of a whole

Front 82

periods

Back 82

horizontal rows that tells how many energy levels it has
nucleus doesn't count as an energy level

Front 83

formaula for knowing how many electrons goes in the cloud

Back 83

2n2
two n squared

Front 84

protium

Back 84

hydrogen isotope with 0 neutrons

Front 85

deuterium

Back 85

hydrogen isotope with 1 neutron

Front 86

tritium

Back 86

hydrogen isotope with 2 neutrons