What are the physical properties of solids and liquids and gases?
The basic “stuff” here is that solids have a “definite” or “fixed” shape, and they resist a change of that shape. The common masonary brick is an example. A liquid “deforms” and takes the shape of its container. It has little resistance to shear forces that would change the form it takes. You can put your finger into a glass of water and the water will “allow” you to do that. A gas just disperses as broadly and widely as it can. If you pop a helium balloon, the helium mixes with the air where ever the balloon was popped and then just “gets lost” in all the volume it can. Whether its a closet or a living room, away it goes to be everywhere.
