Water takes any shape

The idea

Liquids have a fixed volume but no fixed shape: their particles are slightly farther apart than in solids (ice is an exception), attractions are slightly weaker, and particles move freely within a limited space.

Pour it around

Some water is in a measuring cylinder, up to a mark. We pour it into a glass, then a bowl, then a flask.

Does the volume of the water change?

• No, only its shape changes
• Yes, it grows in a wide bowl
• Yes, it shrinks in a narrow flask

Pour the water

Pour the water into each container. Then pour it back into the measuring cylinder.

The liquid state

Liquids have a fixed volume but no fixed shape. Their particles are slightly farther apart than in solids (ice is an exception), the attractions are slightly weaker, and the particles move freely within a limited space.

Ice is an exception: the particles of ice are farther apart than those of water. Also, if a container is not clean, some water sticks to its walls, so the level may come out slightly lower.

• What we see | Why (particles)
• Water takes the shape of each container | Its particles are free to move
• It reaches the same mark again | Its particles stay close: they move only within a limited space
• A finger moves easily through water | Attractions are slightly weaker than in solids

Notes

Liquids have a fixed volume but no fixed shape: particles slightly farther apart than in solids (ice is an exception), attractions slightly weaker, particles move freely within a limited space.

Check yourself

Water is poured from a glass into a bowl. What changes?

You can move your finger through water, but not through a wooden block. Why?

How do the particles of a liquid move?

Which is true about ice and water?

• Both its shape and its volume. A liquid has a fixed volume. Only the shape changes.
• Only its volume. A liquid keeps its volume. It is the shape that changes.
• Only its shape — correct. Yes. Its volume stays the same.
• Water particles have no attraction at all. They still attract strongly enough to stay close together. That is why water keeps its volume.
• Water has no particles. Water is made of particles too. They are held a little less strongly.
• Attractions between particles are slightly weaker in liquids than in solids — correct. Yes. The water moves aside, and comes back when you take your finger out.
• They move freely and fill all the space they get. That is a gas.
• They only vibrate about fixed positions. That is a solid.
• They move freely, but only within a limited space — correct. Yes. So a liquid flows but keeps its volume.
• The particles of ice are closer together than those of water. For most substances the solid's particles are closer, but ice is an exception.
• The particles of ice are farther apart than those of water — correct. Yes. Ice is the exception to the usual rule.
• There is no space at all between the particles of ice. There is some space between the particles even in solids.