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NCERT Solutions for Class 6th Science Chapter 8 .3 What are the Different States of Water? (Table 8.3) — Activity 8.5: Let us identify

Book page 1508 Updated on2026-09-19

Q1.
Put an ice cube in one container and transfer it to another container of different shape. What changes do you notice in the shape of the ice cube?
Answer

No change at all. The ice cube keeps its own shape — it is still a cube, whichever container you put it in.

  • Put it in a round katori — it stays a cube.
  • Tip it into a tall glass — it stays a cube.
  • Put it on a flat plate — it stays a cube.

The only change is that it slowly gets smaller and its corners become rounded, but that is melting, not the container acting on it.

Why a solid keeps its shape: in ice the particles are packed in a fixed, regular arrangement and are held tightly in place. They can vibrate but cannot move from their positions, so the block as a whole cannot change form. This is the defining property of the solid state.
Check it yourself: Try the same with a marble, a piece of chalk and a rubber. None of them takes the shape of its container either — all solids behave this way.
Q2.
Pour water from one container to another container of a different shape. Observe how water behaves compared to the ice cube. Did you notice how water flows from one container to the other? What happens to its shape?
Answer

Water behaves in exactly the opposite way to ice.

  • It flows smoothly and continuously from one vessel to the other — you can pour it, and it takes the shape of the stream while pouring.
  • It takes the shape of the new container completely. In a round bowl it is round, in a square box it is square, in a tall glass it is a tall column.
  • It has a flat, level upper surface in every container.
  • Its amount does not change. 200 mL poured from a bowl into a glass is still 200 mL. The shape changed; the volume stayed constant.
Why a liquid behaves like this: in water the particles are still close together — which is why the volume does not change — but they are not locked in fixed places. They can slide past one another. So the water can rearrange itself to fit any vessel, and it can flow.
Tip: Note carefully — a liquid has a definite volume but no definite shape. A solid has both. Getting this pair right answers most questions on states of matter.
Q3.
Pour water on a clean surface and observe how it spreads. Record your observations in Table 8.3.
PropertyIce
(Solid state)		Water
(Liquid state)		Water vapour
(Gaseous state)
Shape   
Ability to flow   
Ability to spread   
    
Table 8.3, page 150 — Compare different states of water (blank, as printed).
Answer

Observation: the water does not stay in a heap. It spreads out over the surface into a thin, flat sheet, and keeps spreading until it is stopped by an edge or by a groove.

Notice also that the amount does not change — the same water simply covers a larger area in a thinner layer. Water spreads while keeping its volume constant.

Here is Table 8.3 completed:

PropertyIce (solid state)Water (liquid state)Water vapour (gaseous state)
ShapeFixed — keeps its own shape in every containerNo fixed shape — takes the shape of the containerNo shape at all — fills the whole container
Ability to flowDoes not flowFlows easilyFlows and moves freely in every direction
Ability to spreadDoes not spreadSpreads over a surface, volume staying the sameSpreads out into the entire available space
Why ice does not spread but water does: spreading needs the particles to move past one another. In ice they cannot; in water they can.
Q4.
When water gets converted into water vapour, how does this water vapour spread? Compare this with the spreading behaviour of water.
Answer

Water vapour spreads out into the entire space available to it — in every direction, upwards as well as sideways — until it is evenly mixed through the whole room or the whole container.

Point of comparisonWater (liquid)Water vapour (gas)
Direction of spreadingSideways along a surface only; it cannot climbEvery direction, including upwards
How far it spreadsUntil stopped by an edge; it stays at the bottom of a vesselUntil it has filled the whole vessel or room
VolumeConstant — 200 mL stays 200 mLNot fixed — it expands to whatever volume it is given
Upper surfaceHas a flat, level surfaceHas no surface at all
Can you see it?YesNo — it is invisible
Why a gas spreads so completely: in water vapour the particles are very far apart and move very fast, in all directions. There is almost nothing holding them together, so they keep moving until they are spread evenly everywhere. This is why a gas has neither a fixed shape nor a fixed volume.
Everyday proof: a wet floor stays wet only where the water is, but the smell of a chapati on the tawa reaches the whole house within a minute. Gases spread; liquids do not.
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