Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

8th Grade Science > Chemistry > Flashcards

Chemistry Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Definition of Matter

A

has mass; takes up space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

States of Matter

A

Solid, Liquid, Gas, Plasma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Solid

A
  • definite shape
  • definite volume
  • molecules move slowly (vibrate)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Liquid

A
  • indefinite shape

* definite volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Gas

A
  • indefinite shape

* indefinite volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Plasma

A
  • indefinite shape
  • indefinite volume
  • molecules move really fast
  • electrically-charged particles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Definition of Shape

A

a particular form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Definition of Volume

A

amount of space an object occupies (takes up)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Definition of Mass

A

amount of matter in an object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Kinetic Theory of Matter

A

the theory that all matter is made up of tiny particles that are in constant motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Thermal Expansion

A

a characteristic of matter causing it to expand when heated and contract when cooled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are particles like in a solid?

A
  • very close together

* vibrate in position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are particles like in a liquid?

A
  • close together

* move over each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are particles like in a gas?

A
  • seperate from one another

* move in all directions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are particles like in a plasma?

A
  • seperate from one another
  • move in all directions
  • gas-like
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are Crystalline Solids?

A

solids whose particles are arranged in repeating geometric patterns called crystals (most solids)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Examples of Crystalline Solids

A

Rock, Tree

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are Amorphous Solids?

A

solids that are not made out of crystals (they slowly change shape)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Examples of Amorphous Solids

A

Wax, Play-Doh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What do liquids do in a container?

A

they take the shape of the container

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Examples of Liquids

A

Milk, Soda

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does a gas do in available space?

A

it expands and contracts to fill the available space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Examples of a Gas

A

Carbon Dioxide, Helium in a tank

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the most common form of matter in the universe?

A

Plasma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is most of our solar system’s mass composed of?

A

99% of our solar system’s mass is composed of the sun

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Because of extremely high temperatures, particles in plasma do what?

A

move more rapidly, collide, and break into smaller charged particles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Examples of Plasma

A

Stars (i.e. The Sun), lightning, fire

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Going from a Solid to a Liquid is called…

A

melting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Going from a Liquid to a Solid is called…

A

freezing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Going from a Gas to a Liquid is called…

A

condensation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Going from a Liquid to a Gas is called…

A

evaporation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Going from a Solid to a Gas is called…

A

sublimation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is Evaporation?

A

change of a substance from a liquid state to a gaseous state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

example of Evaporation

A

a puddle disappears on a sunny day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is Condensation?

A

change of a substance from a gaseous state to a liquid state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

example of Condensation

A

water on the outside of a cold glass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is Sublimation?

A

a type of evaporation in which a solid changes directly to a gas without going through a liquid state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

example of Sublimation

A

dry ice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is a Change of State?

A

the conversion of a substance from one physical form to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the difference between Endothermic Changes and Exothermic Changes?

A

energy is added during endothermic changes. energy is removed during exothermic changes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

The Freezing Point and Boiling Point of a substance…

A

are the same temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What do both Boiling and Evaporation result in?

A

a liquid changing to a gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Condensation is…

A

the change of a gas to a liquid // the reverse of evaporation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What does Sublimation do?

A

Sublimation changes a solid directly to a gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

During a Change of State, what does the temperature of a substance do?

A

nothing; the temperature if a substance does not change during a change of state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What are Physical Properties?

A

a characteristic of matter that can be observed or measured WITHOUT CHANGING the identity of the matter

47
Q

examples of Physical Properties

A

length, mass, volume, density, odor, color, state of matter, flexibility, texture, shape, magnetic

48
Q

What are Chemical Properties?

A

a characteristic of matter that describes its ABILITY TO CHANGE into NEW MATTER with DIFFERENT properties

49
Q

examples of Chemical Properties

A

flammability, reactivity (can react with another substance to form something new), potential to rust and/or rot

50
Q

What is a Physical Change?

A

a change of matter from one form to another that affects one or more physical properties

51
Q

What is a Chemical Change?

A

a change that occurs when one or more substances change into new substances with different properties

52
Q

It could be a physical change if the substance…

A
  1. Changes shape
  2. Dissolves
  3. Changes State/Phase
  4. Changes color
53
Q

What makes something a physical change?

A

No matter what, the substance is still the same

54
Q

It could be a chemical change if a substance…

A
  1. Changes color because of a chemical reaction
  2. Gives off gas/bubbles (forcefully)
  3. Burns
  4. Forms a new substance
  5. Gives off heat
  6. Feels cold
55
Q

What is an Exothermic Reaction vs. an Endothermic Reaction?

A

exothermic reaction - substance gives off heat

endothermic reaction - substance feels cold

56
Q

What is an example of the physical property Solubility?

A

a flavored drink mix DISSOLVES in water

57
Q

What is an example of the physical property Thermal Conductivity?

A

plastic foam protects you from hot liquid

58
Q

What is an example of the physical property Malleability?

A

aluminum can be FLATTENED into sheets of foil

59
Q

What is an example of the physical property Ductility?

A

copper can be PULLED INTO THIN WIRES

60
Q

What is an example of the physical property Odor?

A

an onion gives off a very distinctive SMELL

61
Q

What is an example of the physical property Density?

A

a golf ball has MORE MASS than a table tennis ball, but the VOLUMES ARE SIMILAR

62
Q

When a substance undergoes a physical change, what is not changed? What is changed?

A

its composition does not change. only a physical property is changed.

63
Q

The chemical property that describes the ability of 2 or more substances to combine to form new substances is called…

A

reactivity

64
Q

The ability of a substance to burn is a chemical property known as…

A

flammability

65
Q

An iron nail is reactive with…

A

oxygen in the air (reaction: rust)

66
Q

What is a Characteristic Property of matter?

A

either a physical or chemical property that scientists use to help identify & classify matter

67
Q

Does a substance always have chemical properties?

A

yes, even though they are difficult to observe

68
Q

How do you know that baking a cake involves chemical changes?

A

Baking a cake involves chemical changes because the cake’s properties differ from the properties of the ingredients before they were baked.

69
Q

Why are chemical changes hard to reverse?

A

because they change the identity of the substances involved

70
Q

What is the most important question to ask to determine whether a change is physical or chemical?

A

Did the composition change? (chemical ~ yes; physical ~ no)

71
Q

What is the name of the process by which water is broken down into hydrogen and oxygen using an electric current?

A

electrolysis

72
Q

What are Elements?

A

They’re pure substances made of only 1 kind of atom.

73
Q

What are Atoms?

A

They’re tiny structures found in all matter.

74
Q

What do most substances contain?

A

many different atoms. only the elements contain only 1 kind of atom

75
Q

Elements:

A
  1. One kind of atom
  2. Pure
  3. Seperated in nuclear reactions
76
Q

Compounds:

A
  1. 2 or more kinds of atoms chemically bonded
  2. Pure
  3. Seperated in chemical reactions
77
Q

Mixtures:

A
  1. 2 or more elements or compounds physically together
  2. Not pure
  3. Seperated in physical reactions
78
Q

A substance that cannot be seperated into simpler substances by physical or chemical means is…

A

an element

79
Q

What do elements contain only 1 of?

A

contains only 1 type of atom

80
Q

Where can elements be found?

A

on the periodic table

81
Q

What are the 3 major categories of elements?

A

metals, nonmetals, and metalloids

82
Q

examples of elements:

A

Helium, Iron, Calcium

83
Q

A subtance made of 2 or more elements that are chemically combined is…

A

a compound

84
Q

What does a compound have a specific ratio of?

A

a specific ratio of elements (formula)

85
Q

How do the properties of the compound compare to the elements it’s made from?

A

properties of the compound are different than the individual elements it’s made from

86
Q

examples of compounds:

A

Table Salt -> Sodium & Chlorine: NaCl
Sugar (sucrose) -> Carbon, Hydrogen, & Oxygen: C H O
12 11

87
Q

A combination of 2 or more substances not chemically combined is…

A

a mixture

88
Q

Do the properties of substances change when forming a mixture?

A

no; no change in original properties of substances

89
Q

Is there a specific ratio of substances when forming a mixture?

A

no; formed by using any ratio of substances (# of choc. chips in a cookie doesn’t matter; it’s still a choc. chip cookie)

90
Q

examples of mixtures:

A

Hot Chocolate, Bowl of Cereal, Salt Water

91
Q

This represents the element. While te English name sometimes matches, the Latin name was sometimes used to create this.

A

Element Symbol

92
Q

This is the most commonly used word for the element.

A

Element Name

93
Q

Designated by the number of protons in the nucleus, this determines hotizontal placement on the table.

A

Atomic Number

94
Q

This is determined by the weight of an atom.

A

Atomic Mass

95
Q 
LABEL THE PARTS:      
       6
       C
  Carbon
12.01115
A
  1. Atomic Number
  2. Element Symbol
  3. Element Name
  4. Atomic Mass
96
Q

Periodic Table of Elements:

A

the arrangement of elements according to repeating changes in properties

97
Q

How are elements arranged?

A

Elements are arranged in order of their ATOMIC NUMBER - not atomic weight

98
Q

What are vertical columns called, and what do elements in each vertical column have in common?

A

Vertical columns are called groups or families. There are 18 groups. Elements in each group or family have similar properties.

99
Q

What determines element’s properties?

A

Similar electron arrangements determine element’s properties. The number of electrons in the outer energy level determines the chemical properties of that element.

100
Q

What are horizontal rows of elements called?

A

Horizontal rows if elements are called periods.

101
Q

Where are elements that are METALS placed on the periodic table?

A

All elements to the LEFT of the stair step line are METALS (except hydrogen)

102
Q

What are common properties of metals?

A

metals are commonly solid at room temperature, shiny, and good conductors of heat & electricity

103
Q

Where are elements that are NONMETALS placed on the periodic table?

A

All elements to the RIGHT of the stair step line are NONMETALS

104
Q

What are common properties of nonmetals?

A

Nonmetals are commonly gases or brittle solids at room temperature, and most do not conduct heat & electricity well

105
Q

Where are elements that are METALLOIDS placed on the periodic table?

A

All elements NEXT TO the stair step line are METALLOIDS

106
Q

What properties do metalloids have?

A

Metalloids have properties of both metals & nonmetals

107
Q

What elements are TRANSITION ELEMENTS?

A

All elements in GROUPS 3-12 are TRANSITION ELEMENTS

108
Q

What are transition elements?

A

Transition elements transition from very metallic to nonmetallic properties

109
Q

Why are elements in group 18 called the noble gases?

A

They don’t react with other elements.

110
Q

What does it mean if an element is synthetic?

A

It means the element is manmade.

111
Q

Separation of Mixtures:

Evaporation

A

a mixture is heated until the water changes from a liquid to a gas. the water vapor can be collected & condensed back into liquid form. the reamainin substance has then been separated from the water.

112
Q

Separation of Mixtures:

Sifting/Filtering

A

a mixture is passed through a screen that separates large particles from small particles. the smaller particles pass through while the larger particles are collected on the screen.

113
Q

Separation of Mixtures:

Weight

A

a special machine called a centrifuge spins a mixture to separate substances with different masses. the heavier substance is forced to the bottom & the liquid is siphoned off.

114
Q

Separation of Mixtures:

Magnetism

A

a magnet is used to separate magnetic materials from those that are not magnetic.

8th Grade Science (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions