What is Matter?
States of Matter
Matter takes the following forms: solid, liquid, gas and plasma. We will be focusing on solids, liquids and gases. Let's go over some key differences between these three forms.
Watch the following video
Next, we need to talk about the terms intermolecular forces, order and degree of freedom and how these terms relate to these three phases of matter.
- Intermolecular Forces: They are the forces that exist between molecules. Think of intermolecular forces as the glue that holds particles together.
- Solids have the highest intermolecular forces meaning they have a stronger glue holding them together which is why they stay the same shape. Think of the intermolecular forces in solids as gorilla super glue. It will hold two items together very well.
- Liquids are the middle man. They have slightly weaker intermolecular forces than solids which is why they are able to take the shape of the container and move around more. Think of the intermolecular forces in liquids as stick glue. It will kind of hold two things together.
- Gases have the weakest intermolecular forces. Most websites say the intermolecular forces are negligible (not there/not important), but keep in mind gases do have intermolecular forces, but they are very, very weak. It would be like not using glue at all to hold two things together which is why gases fly everywhere.
- Order: Is how neatly the particles are arranged.
- Solids are very neat and orderly. They stay tightly together.
- Liquids have some order, but they move around a little.
- Gases don't have any order. Gases move everywhere.
- Degree of Freedom: How much can the particles move?
- Solids have the lowest degree of freedom. Solids don't move very much.
- Liquids have some degree of freedom, and can move around a little.
- Gases have the greatest degree of freedom. Gases can move everywhere.
Attribution: Kh1604, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons
We have discussed three phases, and now we need to discuss phase changes. Matter is not "Stuck" in one state, it can change from from one state to another.
- Evaporation: Liquid to a gas
- Melting: Solid to a liquid
- Condensation: gas to a liquid
- Freezing: liquid to a solid.
- Sublimation: solid to a gas (no liquid stage)
- Deposition: gas to a solid (no liquid stage)
- Solid = ice
- Liquid = water
- Gas = water vapor (steam)
Heating Curve of Water
Phase Changes Lab
What happens when you change the states of matter?