This document describes the differences between freezing, melting, and evaporation. It defines these terms and explains factors that influence their rates. Freezing is a change from liquid to solid, melting is solid to liquid, and evaporation is liquid to gas below the boiling point. Temperature, size/shape, conduction, humidity, and composition affect rates. Higher temperatures speed melting and evaporation, while lower temperatures speed freezing. Smaller pieces melt/freeze faster due to more surface area. Good conductors transfer heat/cold faster. Evaporation is slowest in high humidity.

1. Freezing, Melting,
and Evaporation
SPI 0507.9.2 Describe the differences among
freezing, melting, and evaporation.
SPI 0507.9.3 Describe factors that influence the
rate at which different types of material freeze,
melt, or evaporate.

2. Part 1 - Definitions






Melting
Freezing
Boiling
Evaporating
Condensing
Sublimating

3. Melting
To melt means to change
a substance from a solid
to a liquid state by
heating it to the melting
point. Different
substances melt at
different temperatures.
Water melts at 0°C or
32°F.

4. Freezing
To freeze means to
change a substance
from a liquid to a solid
state by cooling it to the
freezing point.

5. Temperatures


The freezing and melting temperatures for
most substances are the same.
For water this is 0°C or 32°F.
Read Workbook pages 180-181

6. Boiling Point
The boiling point is
the temperature at
which a liquid
changes to a
vapour or gas.
Again this is a
different temperature
for different
substances. For
water the boiling
point is 100°C or
212°F.

7. Evaporation
Evaporation is the change
of a liquid into a vapor at
a temperature below the
boiling point. This occurs at
any temperature between
the melting point and the
boiling point. However, the
warmer the temperature
the more quickly the water
will evaporate.

8. Condensation
Condensation is the change
of a gas or vapor to a liquid,
either by cooling it or by
subjecting the substance to
an increase in pressure.
When water vapor cools in
the atmosphere, it condenses
into tiny drops of water which
form clouds.
Read Workbook page 187

9. Sublimation
Sublimation is the
process of changing
from a solid to a
gas without passing
through a liquid
phase.
Read Workbook page 188

10. Practice –
Number your paper from 1 to 10.
Decide the state or phase for each item. Is it . . .
 Melting
 Freezing
 Boiling
 Evaporating
 Condensing
 Sublimating

11. 1. In which state is the snow?
a)
b)
c)
d)
e)
f)
Melting
Freezing
Boiling
Evaporating
Condensing
Sublimating

12. 2. In which state is the puddle?
(Choose 2 answers.)
a)
b)
c)
d)
e)
f)
Melting
Freezing
Boiling
Evaporating
Condensing
Sublimating

13. 3. In which state is the fog?
a)
b)
c)
d)
e)
f)
Melting
Freezing
Boiling
Evaporating
Condensing
Sublimating

14. 4. In which state is the moisture on
the bottle?
a)
b)
c)
d)
e)
f)
Melting
Freezing
Boiling
Evaporating
Condensing
Sublimating

15. 5. In which state is the puddle on the
road?
a)
b)
c)
d)
e)
f)
Melting
Freezing
Boiling
Evaporating
Condensing
Sublimating

16. 6. In which state is the road?
a)
b)
c)
d)
e)
f)
Melting
Freezing
Boiling
Evaporating
Condensing
Sublimating

17. 7. In which state is the moisture on
the leaf petals?
a)
b)
c)
d)
e)
f)
Melting
Freezing
Boiling
Evaporating
Condensing
Sublimating

18. 8. In which state is the water in the tea
pot?
a)
b)
c)
d)
e)
f)
Melting
Freezing
Boiling
Evaporating
Condensing
Sublimating

19. 9. In which state is the ice next to the
mountain?
a)
b)
c)
d)
e)
f)
Melting
Freezing
Boiling
Evaporating
Condensing
Sublimating

20. 10. In which state is the water vapor?
a)
b)
c)
d)
e)
f)
Melting
Freezing
Boiling
Evaporating
Condensing
Sublimating

21. Answers

22. 1. In which state is the snow?
a)
Melting

23. 2. In which state is the puddle?
a)
b)
Melting
Freezing

24. 3. In which state is the fog?
e) Condensing

25. 4. In which state is the moisture on
the bottle?
e) Condensing

26. 5. In which state is the puddle on the
road?
d) Evaporating

27. 6. In which state is the road?
b) Freezing

28. 7. In which state is the moisture on
the leaf petals?
e) Condensing

29. 8. In which state is the water in the tea
pot?
c) Boiling

30. 9. In which state is the ice next to the
mountain?
f) Sublimating

31. 10. In which state is the water vapor?
d) Evaporating

32. Part 2
Factors that
influence the rate
of Evaporation

33. Video
video.flv
video.mp4

34. Factor 1 - Temperature
The higher the temperature the faster the rate
of evaporation.

35. Which puddle will evaporate faster?
A
B

36. Factor 2 - Wind

The more wind or air circulation the faster
the rate of evaporation.

37. Which puddle will evaporate faster?
A
B

38. Factor 3 – Exposed Surface Area
The larger the exposed surface area the
faster the evaporation rate.
1 inch
3 inches
The water will evaporate more quickly from
the beaker on the right with the wider
opening.

39. If each beaker contains 8 ounces of water,
which beaker will evaporate the quickest?

40. Factor 4 - Humidity

When humidity (the amount of water vapor
in the air) is high, evaporation is slower.

41. In which location would laundry
hanging on a line dry the quickest?
A) Desert
Humidity = 30%
B) Nice Day
Humidity =60%
C) Rainy Day
Humidity = 100%
D) Tropics
Humidity = 90%
Read Workbook page 189

42. Online Activity
Effect of Humidity & Temperature on
Evaporation
http://www.fossweb.com/modules3-6/Water/act

43. Part 3
Factors that
influence the rate of
Melting or Freezing

44. Factor 1 - Temperature
Remember the freezing/melting point of water
is 0°C or 32°F.
The higher the temperature the faster water
will melt.
The lower the temperature the faster water
will freeze.

45. Factor 2 - Size and Shape
If you have two equal masses of ice – one
in a solid block and the other in smaller
pieces - the smaller pieces will melt faster.

46. Factor 2 - Size and Shape (cont.)
Just like with evaporation, the more surface
area exposed to heat the faster water will
melt. Likewise, the more surface area
exposed to cold, the faster water will
freeze.

47. In which cup will the ice melt quicker?
A
B

48. Factor 3 – Conduction
Think about this. People control the
temperature of food by placing it into
styrofoam containers. Styrofoam is a poor
conductor of heat. A styrofoam container
will not change temperature quickly. This is
why when you buy a cup of hot chocolate, it
will probably come in a styrofoam cup. Your
hot chocolate will stay warm longer and
your hand will not get burned.

49. Heat Transfer
If you place equal amounts of hot water into
two containers - a metal container (a good
conductor of heat) and a wooden container
(a poor conductor of heat) - the water in the
metal container would cool faster.

50. Cold Transfer
Any time you place equal amounts of water
at the same temperature into two
containers – one a good conductor of heat
and one a poor conductor of heat. The
container made from a good conductor of
heat will speed up the cooling of the water
by conduction.

51. In which cup could you freeze 6
ounces of water the fastest?
A) plastic
B) metal
C) Styrofoam
D) wood

52. Factor 4 – Changing the Composition
During the cold and icy winter, you have
probably experienced salt on sidewalks and
roads. It is used to melt the ice and snow
and keep it from refreezing. The freezing
point of water becomes lower as more
particles are added until the point where the
salt stops dissolving.

53. By adding salt to icy roads, you change the
freezing/melting from 0°C to point to -9°C.

54. Review – Four Factors that influence the rate
of Melting or Freezing

Factor 1 – Temperature (The hotter the air
temperature the faster ice melts; the colder
the air temperature faster water freezes.)

Factor 2 - Size and Shape (Larger pieces of
ice melt more slowly than an equal mass of
smaller pieces.)

55. 

Factor 3 – Conduction (Water in containers
which are good conductors of heat will cool
more quickly.)
Factor 4 – Changing the Composition
(Mixing water with other compounds such
as salt will influence the melting/freezing
point.)

56. Practice –
Number your paper from 1 to 12.
Answer the following questions about factors
that influence the rate at which different
types of material freeze, melt, or evaporate.

57. 1. Falling temperatures can affect the
water cycle by ______.
a)
b)
c)
d)
creating larger
raindrops
changing
precipitation from
rain to snow
creating smaller
raindrops
changing the path
of water runoff

58. 2. How does adding salt to water affect
the temperature?
a)
b)
c)
d)
The melting point increases to a higher
temperature.
The freezing point increases to a higher
temperature.
Salt does not affect the temperature of
water.
The freezing point decreases to a lower
temperature.

59. 3. Under which of the following conditions
will water evaporate the slowest?
a) Humidity = 95%
b) Humidity = 80%
c) Humidity = 30%
d) Humidity = 70%

60. 4. You are going camping for three days. You need to
buy ice that will keep your ice chest cool for the entire
3 day trip. Which would be the best ice to buy?
a) one large
block of
ice
b) many small
cubes
c) crushed
ice
d) brightly
colored
cubes

61. 5. At which of the following ground
temperatures will the puddle evaporate the
fastest?
a) 50°C
b) 15°C
c) 29°C
d) 87°C

62. 6. Your little sister forgot to turn off the water in the bathroom
sink. The water overflowed and soaked the carpet. You want to
dry the carpet out before your mother gets home. At which level
should you turn on the fan?
a) low
b) high
c) medium
d) The carpet would dry
out faster without a fan.

63. 7. Students are investigating whether wind affects
the rate at which the sponge will dry. Which
experiment is best to use in answering their
question?
a)
b)
c)
d)

64. 8. Which cup will keep your coffee hot
for the longest amount of time?
a) silver
b) copper
c) styrofoam
d) steel

65. 9. Each of the following containers hold
exactly10 ounces of water. From which
container will water evaporate the fastest?
a)
b)
c)
d)

66. 10. Which letter represents
evaporation?

67. 11. At which temperature will the the
icicles elt the quickest?
a) 50°C
b) 15°C
c) 29°C
d) 87°C

68. 12.

69. Answers

70. 1. Falling temperatures can affect the
water cycle by ______.
a)
b)
c)
d)
creating larger
raindrops
changing
precipitation from
rain to snow
creating smaller
raindrops
changing the path
of water runoff

71. 2. How does adding salt to water affect
the temperature?




The melting point increases to a higher
temperature.
The freezing point increases to a higher
temperature.
Salt does not affect the temperature of
water.
The freezing point decreases to a lower
temperature.

72. 3. Under which of the following conditions
will water evaporate the slowest?
a) Humidity = 95%
b) Humidity = 80%
c) Humidity = 30%
d) Humidity = 70%

73. 4. You are going camping for three days. You need to
buy ice that will keep your ice chest cool for the entire
3 day trip. Which would be the best ice to buy?
a) one large
block of
ice
b) many small
cubes
c) crushed
ice
d) brightly
colored
cubes

74. 5. At which of the following ground
temperatures will the puddle evaporate the
fastest?
a) 50°C
b) 15°C
c) 29°C
d) 87°C

75. 6. Your little sister forgot to turn off the water in the bathroom
sink. The water overflowed and soaked the carpet. You want to
dry the carpet out before your mother gets home. At which level
should you turn on the fan?
a) low
b) high
c) medium
d) The carpet would dry
out faster without a fan.

76. 7. Students are investigating whether wind affects
the rate at which the sponge will dry. Which
experiment is best to use in answering their
question?
a)
b)
c)
d)

77. 8. Which cup will keep your coffee hot
for the longest amount of time?
a) silver
b) copper
c) styrofoam
d) steel

78. 9. Each of the following containers hold
exactly10 ounces of water. From which
container will water evaporate the fastest?
a)
b)
c)
d)

79. 10. Which letter represents
evaporation?

80. 11. At which temperature will the icicles
melt the quickest?
a) 50°C
b) 15°C
c) 29°C
d) 87°C

81. 12.