States of
Matter
Q: What do a piece of wood,
a cup of milk, and smoke from a fireplace have in common?
A: They are all types of
matter.
Each one of
those items is made up molecules and
atoms,
but what makes them unique from one another is arrangement of those
molecules and atoms.
There are three states of matter,
these states are are part of the physical
properties of the substance:
Solids
If you look
around you right now, you will see solids all around. The chair you
are sitting on, the screen in front of you and the mouse in your
hand.
Each one of these solids are made of molecules, the molecules are tightly
packed and do not move very much.&
Here is an example of the molecules in a solid:
Liquids
Every morning
that you have a bowl of cereal and you grab the carton of milk from the
fridge, you are looking at a liquid. The molecules in a liquid have
more space between themselves, thus they have more room to move
around. Liquids take the shape of their container, but do not expand to
fully fill their container!
Here is an example of the molecules in a liquid:
Gases
Take a deep
breath...and exhale. The air that you inhale and exhale are both
gases. The molecules in a gas have a much greater space than either
the liquid or the solid. Thus they are able to move around much more
rapidly. One defining characteristic of a gas is that it is able
to take the shape of the container in which it is placed.
Here is an example of the molecules in a gas:
Now you try it:
Materials:
One cup of cornstarch
approximately 1/4 cup of water
Mix the two materials
and make observations, and classify the substance as a liquid, solid or
a gas.
Q: Name one substance that
you can find in all three states of matter on earth?
A: Water; It is
found
as liquid water, Ice and Steam.
You may be wondering how water can be in all of these
states. States of matter are not static, that is the substance can
change from one state to another under certain conditions.
This process of changing states of matter is known as
phase change.
Phase
Changes
There are 6 phase changes that matter can undergo
(along with phase changes, matter can also undergo
physical changes), we can see all
three of these in water. They are the different ways matter can go from
one state to another:
MELTING
This occurs when a solid becomes a liquid, take
out a piece of ice from the fridge and watch it become liquid
water. The opposite of this process is:
FREEZING
This is the process of a liquid
becoming a solid. Fill up the ice cube tray and place it back in
the fridge and watch the water freeze.
BOILING
This is the process where a
liquid becomes a gas. If you boil water you can see the
steam leaving the water surface, the opposite of this process is:
CONDENSATION
This is the process where a gas
becomes a liquid. If you place your hand over the steam from a pot
of boiling water, you will notice your hand getting moist, this is the
steam becoming liquid water again.
SUBLIMATION
This is the process of a solid becoming a gas.
The best example of this is "dry ice" placed in water, the solid carbon
dioxide quickly becomes gaseous carbon dioxide.
