Kinetic Theory of Matter
When explaining how matter works under different situations, scientists use the model of the kinetic theory of matter.
The theory illusrtates how matters react under different temperature and energy levels.
The kinetic theory explains three states of matter: gaseous, liquid, and solid.
Main points of theory
All matter is made up of tiny particles, like atoms, molecues and ions. (Discussed in another article)
These particles move all the time. The more energy they have, the faster they move around, and this energy is usually in the form of temperature. This is kind of like giving sugar to kids - the more sugar you give them, the more hyper they get. Different states means different sizes of the space between each particle, while different sized particles means a different substance.
This seems kind of confusing, but actually it is pretty simple.
At a higher temperature, particles move around more, so they move further apart from each other. Thus, the size of the space between each particle shows which state it is in.
However, if the size of each particle is different between two objects, then it means they are of a different substance, e.g. lead and helium. Heavier particles move slower, and lighter particles move faster, at a given temperature.
The different states...
All matter can become a gas, solid or liquid if the temperature is high or low enough. This will be explained in further detail!
Solids:
Examples of solids at room temperature are wood, steel and certain types of plastic. Their properties include:
-Fixed volume
-Cannot flow
-Cannot be compressed or squash
Why?
Solids have the lowest temperature of all three states of any matter - this gives particle relatively less energy and thus they cannot move around as much. Therefore, the space between them is very little, and one cannot compress it, for when you compress an object you are basically decreasing the space between each particle (covered in more details later).
The particles in a solid:
-Packed close together in a regular pattern -Vibrate about a fixed position This is very similar to a packed train on rush hours - everyone is packed together, it is very hard to move around! Also, it is almost impossible for people to squeeze in a make more space! Liquids:
Examples (at room temperature): water, bromine, soft drinks Properties:
-Flows
-Indefinite shape - takes the shape of its container
-Definite volume -Cannot be compressed
Here, the particles have more energy, so the spaces between them are larger - this gives them an indefinite shape as particles can move more freely. Also, the particles can slide over each other so they can flow. However, the spaces between them is limited so they still cannot be compressed. The temperature in which a solid becomes a liquid is known as the melting point.
Particles:
-Close together
-Random movement
-Slides and move around each other Very similar to an indoor gym! People can move around each other but are still confined by the gym and can only take the shape of its containers.
Gases:
Properties:
-Completely fills container
-Can be compressed Particles have high energy so the spaces between them are massive and they move extremely quickly. Gases can be compressed because one can compress the spaces between each particle and they fill their container for they move extremely quickly. Particles:
-Far apart
-Random movement
-Moves in all directions
-Moves very quickly Similar to a school playground at recess where everyone is going crazy! Here's a brief summary:
(There are actually two more states: Plasma and Bose-Einstein. Plasma state is kind of like gas but are made up of ions and electrons, while Bose-Einstein is a hypothetical state where particles do not move at all because they have lost all energy at -273 C or 0 K. You do not need to know these two in comprehensive detail though! Phew!)
