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.
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.
13.
14.
15.
16. If floating is a physical property of a
substance, would changing the size and
shape of the substance make it not float?
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.
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.
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.
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?
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?
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?
82.
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.
85.
86.
87. How can he separate the sticks from
the gravel?