What's the matter?

Do you realize that everything in the universe is made of only 
four basic types of matter! Your computer, a can of soda, the 
air you breathe, and even the stars in the sky are all made of 
one of these four basic types.


All matter is composed of billions of microscopic atoms. 
These atoms combine to form molecules. Molecules are also 
microscopic. There are billions of molecules that form to 
create a tiny drop of liquid, a balloon full of helium, or the 
eraser on a pencil.


Molecules are attracted to each other. Because of this 
attraction, they are held directly next to each other. When 
these molecules bind together, they form one of the four 
states of matter. Depending on the state they are in, 
molecules barely move, doing little more than vibrating in
place, as in a solid, or they can move in a quick, erratic
manner, bouncing against the area in which they are 
contained, which happens with plasma.



To examine the attraction between molecules, think about 
what happens to two magnets. If next to each other, the 
opposite poles pull strongly at each other, and they stay side 
by side. (
solid) If you move the magnets a little bit apart, the 
attraction, or pull, between them is not as strong. (
liquid) If 
you continue to move the magnets apart there is a much 
weaker attraction. (
gas) And finally, if you move the magnets 
even farther away, there is barely any attraction left. (
plasma)


Although all matter is in one of the four states at any given 
time, these states are not necessarily permanent. Water is a 
good example of changing states of matter. In a solid form, 
water is ice. The molecules move slowly. Since they are so 
close to each other, there is a strong attraction between all the
molecules, and they are kept tightly next to each other. All 
molecules move, but since they are packed next to each 
other so closely, molecules in a solid can do little more than
vibrate slightly.


If heat is added to ice, it melts. It has changed states of matter.
It has gone from a solid to a liquid. It still contains the same
molecules, but they are now moving faster. This faster 
movement sends the molecules farther away from each other,
and the attraction between them is not as strong as they were 
in a solid. This allows a liquid to have a less rigid form and
flow to fit the shape of its container.


Finally, as water is heated even more and it evaporates, there
is only a weak attraction between the molecules, and they 
wildly bounce off each other and float off in all directions. 
This state of matter is called a gas.


Visit the following pages for more information on 
the four types of matter.

solid
liquid
gas

plasma

 

changes of state

physical/chemical change

properties of matter

solutions

acids and bases

 

Activities
states of matter          solid/liquid/gas

properties of matter  

physical/chemical changes

states of matter simulator

 

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Questions and comments: lcelaya@amphi.com  last revised 6/2019