Presentation of mechanical properties common to solids.

Solids are characterized by a stable and definite shapeshapeshape and a definite volumevolumevolume.

1. three cuboids made of various materials, e.g. wood, iron, plastic,
2. two vessels of various shapes and small and large volumes.

1. Place cuboids once in a first and then in a second vessel.
2. Try to change the shape of the cuboids by squeezing them firmly.

Solids have a stable and definite shape and a definite volume.

Presentation of mechanical properties common to liquids.

Liquids are characterized by a variable shape and a definite volume.

1. two liquids, e.g. water and oil,
2. two vessels of various shapes,
3. syringe.

1. Pour the liquidliquidliquid into one and then into the other vessel.
2. Repeat the same for the second liquid.
3. Get the first liquid into the syringe, try squeezing it with the syringe plunger.
4. Repeat the same operation for the second liquid.

Liquids take the shapeshapeshape of the vessel they are in, but their volume does not change under pressure.

Presentation of mechanical properties common to gases.

The gases are characterized by a variable shape and a variable volumevolumevolume.

1. two gases, e.g. carbon dioxide from exhaled air and atmospheric air,
2. balloon, syringe.

1. Blow the balloon.
2. Fill the syringe with air.
3. Try to squeeze the air in the syringe using a plunger.
4. Try to squeeze the balloon.

The gases take the shapeshapeshape of the vessel they are in, they fill the entire volume and it is easy to change their volume. They are compressible and expandable.