A liquid is not a fixed shape. It is able to flow freely. Molecules in a liquid are not as tightly packed as in a solid. Liquids cannot be compressed.
How it flows is called “viscosity.” If a liquid is high viscosity it will flow slowly like honey and a low viscosity liquid will flow quickly like water.
Some liquids behave strangely. A non-newtonian liquid is a bit like a liquid and a solid. They change behaviour when a force is applied. Toothpaste becomes runny when it is mixed. Paint becomes thinner when it is stirred. Cream becomes thicker when it is mixed. A non-newtonian liquid does not always take the shape of its container.
In class we put cornflour in a bowl and added a little water. When you put your hand in slowly it sunk in the liquid but if you whacked it hard it acted like a solid.
Written by pupils in P3/4