Change Flashcards
1
Q
Define physical chnage
A
A change that does not alter the chemical nature of the substance, and in which no new chemical substances are formed
2
Q
What are examples of physical change?
A
Phase chnagez
3
Q
What is Kinetic molecular theory also known as?
A
The particle model of matter
4
Q
Define particle model of matter
A
Scientific model used to explain that all matter is made up of particles and to explain the properties and behaviour of matter
5
Q
Define particles
A
atoms, molecules, ions
6
Q
What does the model state?
A
- Made up of atoms
- Particles always moving
- Empty space between
- Forces of attraction
7
Q
How big are the particles?
A
So small - can’t see under microscope
8
Q
When do particles move faster?
A
Heaterd
9
Q
When do particles move slower?
A
Lose heat
10
Q
What exists between spaces?
A
Nothing
11
Q
What does it mean when forces of attraction is strong?
A
Particles are close
12
Q
What does it mean when forces are weak?
A
Particles are far away
13
Q
How close are the particles for solids?
A
Very close together
14
Q
What forces of attraction do solids have?
A
Strong forces of attraction - held tightly togeteht
15
Q
Can solids be compressed?
A
Cannot be compressed
16
Q
How do solids move?
A
Do not flow - vibrate
17
Q
What type of kinetic energy do solids have?
A
Low kinetic energy
18
Q
Shape and volume of solids?
A
Fixed shape and volume
19
Q
Density of solids?
A
High density
20
Q
How close are liquids particles?
A
Close together
21
Q
Forces of attraction of liquids?
A
String but weaker than solids
22
Q
How do liquids move?
A
Slide over each other
23
Q
Can liquids be compressed?
A
Cannot he compressed
24
Q
Why can liquids move easily?
A
Kinetic energy between particles are greater than solids, weaker than gases
25
Volume of liquids?
Fixed volume
26
Shape of liquids?
No fixed shape
27
What are gases particles like?
Well spread out
28
Forces of attraction for gases?
No forces of attraction
29
Compress of gases?
Easy to compress
30
How do particles of gases move?
Very easily - high kinetic energy
31
Volume and shape of gases?
No fixed volume and no fixed shape
32
Density of gases?
Low density than liquids
33
What causes a material to change state?
Heating and cooling
34
Name six phase changes
1. Melting
2. Freezing
3. Evaporation
4. Condensation
5. Sublimation
6. Deposition
35
When does phase change take place?
Particular temperature
36
Define temperature
Average kinetic energy of particles
37
Define melting point
Substance is the so start temperature at which the substance changes from the solid to liquid phase
38
Define boiling point
Constant temperature at which the substance changes from liquid to gaseous phase
39
What is heat?
Form of energy
40
When matter is heated, what happens to particles?
Temperature increases - particles live faster - kinetic energy increase
41
What happens during phase change?
* Temperature remains constant
* Change
* Energy absorbed/released
42
What is there in the change?
Arrangement
Movement
Attractive forces
Spaces between
43
Define chemical change
Change in which the clerical nature of the substances involved changes and nee chemical substances are formed
44
What does chemical change involve?
* Colour change
* Large change in temperature
* Formation of gas - bubbles
* Formation of precipitate - solid
45
What is the difference between the temperature of physical changes and chemical changes?
Chemical change is much much larger than physical change
46
What does a chemical change involve?
Talking of existing bonds and the formation of a new bonds
47
What must happen in order to break bonds?
Energy must be absorbed – endothermic process
48
What happens when you bonds are formed? 
Energy is released – exothermic process
49
Synthesis reaction
Combustion of hydrogen rocket propulsion
50
Define synthesis reaction
One in which two or more simple substances react to form a more complex product
51
What happens when hydrogen is mixed with oxygen?
It can burn with a spark ignition
52
What does hydrogen have stored in it?
Huge amount of energy
53
What happens when hydrogen burns and chemical bonds are broken?
Newborns are made
54
What is large amount of energy released as in hydrogen?
Heat and thrust energy
55
What can thrust energy be transferred as?
To rocket to propel upwards
56
What type of reaction is oxygen and hydrogen?
Exothermic - energy give off
57
What is the decomposition reaction?
Decomposition of hydrogen peroxide
58
Define decomposition reaction 
One in which a single compound breaks down into two or more elements or new compounds
59
Define catalyst
Substance speed up reaction without taking part
60
Potassium permanganate
KMNO4
61
Define combustion
Rapid chemical reaction with oxygen that produces heat and light
62
What is it called when a metal reacts with oxygen?
Metal oxide
63
Appearance of iron + oxygen
Iron (grey) with metallic lustre
Oxygen - colourless
64
Phase of iron + oxygen room temperature
Iron - solid
Oxygen - gas
65
Metal or nonmetal?
iron + oxygen
Fe - metal
O - nonmetal
66
What happens during the reaction of oxygen and iron?
Iron burns
67
Colour of iron after reaction
Dull grey
68
Phase of products - oxygen + iron
Solid
69
Effect of iron + oxygen on litmus paper
Red litmus paper turns blue -
base
70
Word equation of iron and oxygen
Iron + oxygen -> Iron (III) oxide
71
Balanced chemical equation of iron and oxygen
4Fe + 3O2 -> 2Fe2O3
72
Colour of magnesium and oxygen
Mg - grey with lustre
O - colourless, odourless
73
Phase of magnesium and oxygen
Mg - solid
O - gas
74
Metal or nonmetal of magnesium and oxygen
Mg - metal
O - nonmetal
75
Observation of reaction of magnesium and oxygen
Mg burns with a bright white frame
76
Colour if products of magnetism and oxygen
White, powder, brittle
77
Phase of magnesium and oxygen products
Solid
78
Effect of magnesium and oxygen on litmus paper
Red litmus paper turns blue
Base
79
Word equation of magnesium and oxygen
Magnesium + oxygen -> Magnesium oxide
80
Balanced chemical equation of magnesium and oxygen
2Mg + O2 -> 2MgO
81
Define rust
Slow chemical reaction between iron and oxygen in the presence of moisture in the air
82
What is rust a form of?
Iron oxide
83
What is rust made up of?
Iron (III) oxide (Fe2O3)
84
Define corrosion
Chemical process that damaged or weakens a metal or other strong metal
85
What is highly reactive?
Sodium - places in oil to prevent it from reacting with moisture in air
86
Less reactive material
Gold and platinum
87
Where does rust take place?
At surface of an object containing iron, when exposed to sue and water for extended periods of time
88
What is seen on rusty objects?
Red-brown colour - iron oxide
89
Where does rust happen faster?
Coast (near sea)
90
Why is rusting faster at the coast?
More water droplets in air -
salt more corrosive
91
What else makes metals rust faster?
Presence of acid
92
What is an area called if it contains salt and acid?
Corrosive climate
93
How can rusting be prevented?
Place some kind of barrier between surface i’d object and moisture in air
94
Name four barriers of rust
1. Paint
2 Oil/grease
3. Galvanising
4. Electroplating
95
What is paint used for?
Bicycle, car
96
How does paint work?
Adds a barrier, prevent contact with moisture in air
97
Shortcoming of paint
Paint chipping
98
What is oil/grease used?
Chains on bicycle
99
How does oil/grease work?
Oil repels water. prevent water from coming into contact
100
Shortcomings of oil and grease
Needs to be reapplied
101
Used of galvanising
Boats and ships
102
How does galvanising work?
Paint metal coat in thin layer
103
Shortcomings of galvanising
Expensive and needs to be reapplied
104
Uses of electroplating
Cars, trucks and guns
105
How electroplating works?
Despisers thin layer of different metals that do not rust
106
Shortcomings of electroplating
Very expensive
107
What does nonmetals and oxygen create?
Nonmetal oxide
108
What is the colour of carbon and oxygen?
Carbon: black, brittle, dull
Oxygen: Colourless, odourless
109
Phase of solid and gas reactants
C solid
O gas
110
Metal or nonmetal of oxygen and carbon
Nonmetal
111
Observation during carbon with oxygen
Burns with faint orange glow
112
Colour of carbon and oxygen product
Colourless, odourless
113
Phase of magnesium and oxygen product
Gas
114
Effect of magnesium and oxygen on litmus paper
Blue litmus paper turns red
acid
115
Word equation of carbon and oxygen
Carbon + oxygen -> carbon dioxide
116
Balanced chemical equation of carbon and oxygen
C + O2 -> CO2
117
What is coal a form of?
Carbon - fossil fuel
118
What is the colour of sulphur and oxygen?
S - pale yellow, dull powder
O - colourless, oudoutless
119
Phase of sulphur and oxygen reactants
S - solid
O - gas
120
Metal or no metal sulphur and oxygen
Non metal
121
Observation during the reaction of sulphur and oxygen
Burns with blue flame
122
Colour of sulphur and oxygen products
Colourless, sharp pungent odour
123
Phase of sulphur and oxygen products
Gas
124
Effect of products of sulphur and oxygen on litmus paper
Blue litmus turns red
avid
125
Word equation if sulphur and oxygen
Sulphur + oxygen -> Sulphur dioxide
126
Balanced chemical equation of sulphur and oxygen
S + O2 -> SO2
