Disha NEET Physics Guide for classes 11 and 12.pdf
Physical properties of matter..introduction (Teach)
1. Introduction to
Physical Properties
of Matter
By Moira Whitehouse, PhD
2. Properties of matter
•are the characteristics of a substance that we
can observe such as its color and texture.
3. Properties of matter
•are the characteristics of a substance that
you can observe such as its color and texture.
•are characteristics that can be observed
using our senses- sight, smell, touch and
taste.
4. Properties of matter
•are the characteristics of a substance you
can observe such as its color and texture.
•are characteristics that can be observed
using our senses-sight, smell, touch and
taste.
•allow us to distinguish one substance
from another.
5. Let’s look at some of the physical
properties of two substances we all
know--sugar and sand.
6. Let’s look at some of the physical
properties of two substances we all know--
sugar and sand.
The color of a substance is one of its
properties that can be observed using
the sense of sight.
7. Let’s look at the physical properties of
two common substances we all know-
sugar and sand.
The color of a substance is one of its
properties that can be observed using
the sense of sight.
On the next page you will see photos
of sugar and sand. Look at them
carefully. What color are they? (be
specific)
9. If you were specific in your observations, you
might have said, “bright snow-white” for sugar
and “tan” for sand. Color is one of the
properties which allows us to tell which
substance is sugar and which is sand.
10. Another property of a substance is its
odor. Anyone who has tried to smell
sugar and sand knows that neither one
has much of an odor.
11. What about how it feels—its texture
(another property). How does sugar feel
when you rub it between your fingers?
What about sand?
12. Most people say that both sugar and
sand feel rough and grainy.
13. Other physical properties of a substance
include:
•its state of matter at room temperature--
whether it is a solid, liquid or gas
•whether or not it is magnetic—attracted to
a magnet
•whether or not it floats or sinks in water
•whether or not it dissolves in water
•whether it conducts electricity, heat or
sound
14. Let’s take a look at some of these physical
properties of sugar and sand:
•What state of matter is each substance at room
temperature?
•Does either sugar or sand dissolve in water?
•Is either sugar or sand attracted to a magnet?
•We will discuss what substances are conductors of
electricity and heat in another presentation.
15. State of matter:
What state of matter is sugar at room
temperature? a. solid b. liquid c. gas
What state of matter is sand at room
temperature? a. solid b. liquid c. gas
23. Solubility--whether or not a substance
dissolves in water is another physical
property of substances.
Dissolve means to mix evenly. When a
solid dissolves in water, the molecules mix
evenly and the solid seems to disappear.
The resulting liquid is called a solution.
When a substance dissolves, it may lose
some of its physical properties such as
color and feel.
24. •If we mix sugar and water and stir, what
do you predict?
a. The sugar will dissolve in water
b. The sugar will not dissolve in water
25. •What about if we mix sand and water
and stir?
•What do you predict?
a. Sand will dissolve in the water
b. Sand will not dissolve in the water
26. •Below are the photos of two containers, one with a mixture
of sugar and water and the other with a mixture of sand and
water.
•Circle the photo of sugar and water, and check the one with
sand and water.
•Write “dissolved” under the correct photo.
•Write “solution” under the correct photo.
27. Sugar mixes
evenly with water
and dissolves.
Sugar and water
mixed together
form a solution.
28. As long as we are shaking the sand and water,
the two substances mix evenly. But as soon
as we stop shaking the container, the sand
settles to the bottom of the flask. Sand does
not dissolve in water.
29. Imagine that the molecules of water, sugar and sand
have been magnified so we can see them. Circle the
diagram that shows molecules of sugar and water?
Check the one that shows a mixture of molecules of
sand and water? Explain your choices.
30. When sugar is dissolved in water you can
tell the sugar is still there, even though it
becomes invisible. How can you tell
that sugar is still there?
31. Aha, yes, you can use your sense of taste or
touch. When you take a solution of sugar and
water, it tastes sweet. Also, sugar water feels
sticky. The sugar is still there. You just cannot see
it. When you mix sugar with water the
sugarloses its white color and its grainy, rough
32. Yes, sugar dissolves in water along with
other flavors and colors and produces a
solution that tastes sweet.
Sugar dissolved in
water makes the sweet
flavor found in all kinds
of soda pop.
33. Sugar mixed with many substances like
candies
or
cookies
tastes SWEET
34. Sand and sugar are easy to tell
apart. When you look at them you
can immediately tell one from the
other just by their most obvious
physical property—color. But
what about two substances that
look alike, such as sugar and salt.
They have many physical
properties in common.
35. Both:
•are snow white, have little or no smell,
are solids at room temperature and feel
rough and grainy.
39. I’m sure most of you are saying, “And
on what planet do you live?” Sugar
taste sweet and salt tastes, well, salty.
SWEET SALTY
40. In summary:
Physical properties of substances
•are observable characteristics of the
substances
•allow us to distinguish one substance
from another