Reviewing of States of Matter
Matter is all around us. Matter is the air you are breathing. Matter is the computer you are reading from now. Matter is the stuff you touch and see. And it is more. Matter is defined as anything that has mass and takes up space. Matter is found in 3 major states; solid, liquid and gas.
So what is matter made of? All matter is made of atoms. Atoms are the smallest particle of matter.
Matter that is composed of atoms packed tightly together are known as solids. You cannot walk through a solid wall. The matter is packed so tight that it prevents you from moving through it. Solids hold their shape at room temperature. The pencil that you left in the desk at school will still be the same shape when you return tomorrow.
Liquids do not hold their shape at room temperature. There is space between the atoms of a liquid and they move slightly all of the time. Liquids flow or pour and can take on the shape of a container. If the liquid is poured into a wider or narrower container, the liquid will take on that new shape. Even water in a river or a lake has a container ‐ the banks, the bottom, the shore‐they form the container.
Gases not only do not hold their shape at room temperature, they don't even stay put. Gases are always moving. There is so much space between the atoms in gas that you can move around in them easily. When you walk from one side of the room to the other, you have walked through a bunch of gases that make up our air. You barely even know they are there. Gases will take on the shape of their container and can be compressed into a smaller space. Like when we compress air into a balloon ‐ it fills out the balloon shape.
Matter can move from one state to another, but can still be the same substance. A change of state is a physical change from one state of matter to another, for example, from solid to liquid or from liquid to gas.
How does matter move from one phase to another? If the motion of the atoms is altered by pressure or temperature, the state can change too. By lowering the temperature of water, it can freeze into a solid. By heating water, it can become steam which is a gas. Whether solid, liquid or gas ‐ water is still water.
Pressure can change matter from one state to another. Deep in the earth solids turn to liquids because the heavy weight of layers and layers of the earth push down on the solids causing them to turn to liquid magma. This is just one example of how pressure can change matter too.
Other matter changes too, but often only exists in two states or requires the help of humans and technology to move through all three phases. Water is the only matter on earth that can be found naturally in all three - solid, liquid and a gas.
All matter has qualities about it that describe it scientifically. We call these properties. They can explain the physical or the chemical qualities of a matter. Some of the ways that we describe matter are by its color, its shininess, and its state at room temperature or its odor.
Source: http://idahoptv.org/sciencetrek/topics/matter/facts.cfm