This document discusses various physical properties of different materials: - Some materials float in water while others sink, depending on their density. Liquids like oil also float due to being less dense than water. - Only ferromagnetic metals like iron, nickel and cobalt are attracted to magnets. - Metals like copper, aluminum, tin, and brass conduct electricity well, while other materials like wood, rubber and plastic do not. - Metals are also good conductors of heat and are used for cookware, while materials like wood, cloth and plastics insulate heat. - Physical properties can be used to separate mixtures, like using a magnet to remove nails or letting materials float or sink in water

1. Physical Properties
(some examples)
By Moira Whitehouse PhD

2. •Some material floats in water and that is a
physical property. Other material doesn’t.

3. •Some substances are pulled by a magnet.
•Some material floats in water and that is a
physical property. Other material doesn’t.

4. •Some substances are conductors of
electricity (it can pass through them).
•Some substances are pulled by a magnet.
•Some material floats in water and that is a
physical property. Other material doesn’t.

5. •Some substances are conductors of heat
and others are not.
•Some substances are conductors of
electricity (it can pass through them).
•Some substances are pulled by a magnet.
•A physical property of some material is that
it floats in water. Other material doesn’t.

6. •Some substances are conductors of heat
and others are not.
•Some substances are conductors of
electricity (it can pass through them).
•Some substances are pulled by a magnet.
•Physical properties can be used to separate
mixtures of substances.
•Some material floats in water and that is a
physical property. Other material doesn’t.

7. First, lt’s think about
things that float on water

10. If we gaze into a swimming pool we
notice that there are “floaters” and their
are “sinkers”.

11. We will start out with a cork and a rock.

12. What about cork?
One physical property of cork is that it floats in
water.
Likewise, a physical property of this rock is that it
sinks to the bottom in water.

16. If floating is a physical property of a
substance, would changing the size and
shape of the substance make it not float?

17. Cut the cork into little pieces....

19. The cork floats...

20. And so do the small
pieces...

22. What about other substances, would the
size and shape of the substance make a
difference?

23. How about pine wood pieces and sawdust
from pine wood?

24. These tiny pieces of wood (saw dust) float too, until
they soak up too much water and become heavy.

25. Could a liquid also have
a physical property of
floating on water?

26. We can clearly see that the cooking
oil is floating on top of the water.

27. When oil tankers spring leaks and spill their
cargo of oil, it is difficult to clean up the mess.
Because oil floats on water, however, the oil
can sometime be skimmed off of the water.

28. Floating stuff on top of the water can be
skimmed off....

29. And removed from the water.

30. Next, let’s look at some objects to see if they
have the physical property of being pulled by a
magnet. Such objects are called magnetic.

31. Next, let’s look at some objects to see if they
have the physical property of being pulled by a
magnet.
This is a bar magnet. It is almost touching a
lolly-pop stick. The lolly-pop stick does not
move because wood is not magnetic.

32. nickel.......magnetic

33. silver solder....... not magnetic

34. steel paper clips....... magnetic

35. steel drill bit....... magnetic

36. iron bolt....... magnetic

37. cardboard....... not magnetic

38. copper....... not magnetic

39. rubber....... not magnetic

41. zinc....... not magnetic

42. tin....... not magnetic

43. brass....... not magnetic

44. steel washers....... magnetic

45. steel spoon....... magnetic

46. Aluminum foil......non magnetic

47. Knitting yarn......non magnetic

48. “tin can” actually made of steel......magnetic

49. Interesting fact: only the things made of
iron/steel, nickel and cobalt are magnetic.
However, nickel and cobalt are rare and
expensive metals so we see very few things
made of these substances.

50. The next physical property we will
examine is the ability of a substance to
conduct or pass an electric current.
Those things that conduct electricity are
called conductors and if they don’t
conduct, they are called insulators.

51. To find out if a substance is a conductor we
will use this device.
It sends battery power to the light bulb
when there is a connection between the red
and black wires.

52. This magnet is made of iron so it is a
conductor and lets electricity pass through.
Would the light on the tester be lit?

53. We will start with the
silver solder.
It lets the current pass
from the red to the
black wire, and the
light lights.

54. The current does not travel through wood. No light.

55. The current does
not travel
through rubber.
No light.

56. The current
passes through
the nickel and
lights the light.

57. The current
passes through
the zinc and
lights the light.

58. The current
does not travel
through paper.
No light.

59. The current does
not travel through
plastic. No light.

60. The current
passes through
the steel and
lights the light.

61. The current
passes through
the tin and light
the light.

62. The current
passes through
the steel paper
clips and lights
the light.

63. The current passes through the
aluminum foil and lights the light.

64. The current
passes through
the copper and
lights the light.

65. The current does
not pass through
the knitting
yarn. No light.

66. The current
passes through
the brass
washers and
lights the light.

67. We found that the following substances
are conductors of electricity—that
electrons go through them easily:
•tin
•aluminum
•copper
•brass
•zinc
•iron
•silver
What do you notice about all items on
this list of substances?

68. All these
conductors
are metals.

69. Next we will examine some substances
that conduct something else, heat. You
can probably think of some things used in
the kitchen that need to be good
conductors.

70. Sure, saucepans and other pans that we
use to heat food have to be good
conductors of heat in order for heat to
travel from the stovetop or oven to the
food.

71. aluminum
stainless steel
Copper lined with tin
cast iron
All these substances, aluminum, copper, tin and
steel conduct heat. They are all____________.

72. With many modern saucepans you cannot
see the metal the pan is made out of because
they have a inner coating covering the metal
that helps prevent food from sticking or a
hard outer surface.

73. In addition to the metals, here are some
other good conductors of heat?

74. Things that do not conduct heat are called
insulators of heat—substances that do not
allow heat to travel through them easily.

75. What substances do we use to
stop heat from traveling to our
hands when we cook?

76. Yes, cloth, plastic and wood are all poor
conductors of heat. They are heat insulators.

77. Yes, cloth, plastic and wood are all poor
conductors of heat. They are heat insulators.
What things do we wear or what do
animals have to keep the heat from
escaping from their bodies. These are
all poor conductors of heat?

78. ebbiesonnberg at www.flickr.com
nikonjim’s at www.flickr.com
davewinthrow at www.flickr.com
What insulates these
animals—helps keep
the heat inside their
bodies?

79. We wear things like this to insulate
our bodies from the cold?

80. A carpenter had dropped iron nails he was
using to build a house into the sawdust,
sand and small sticks around the building.
How could he separate these substances?
To show how physical properties can be
used to organize or separate things we
will use the following:

81. Here is the mess he wants to
separate..
The first thing he will do is get the nails
out of the pile. How could he do that?

83. OK for the nails,, now he needs to
separate the sand from the gravel and
sticks. Any thoughts?

84. He used a sieve to separate
the bigger stuff from the
sand.

87. How can he separate the sticks from
the gravel?

88. He poured the contents into a
bowl of water.

89. The sticks floated to the top and the
stones fell to the bottom.

90. Skim off the sticks.

92. Pour off the water and
remaining is the clean gravel .

93. Isn’t it amazing what can be
done with just a little knowledge
about physical properties.