NCERT Solutions for Class 6th Science Chapter 8 A Journey through States of Water
Updated on 2026-09-19
About this chapter
Ice, water and water vapour are the same substance in three different states — solid, liquid and gas. Ice keeps its own shape and does not flow; water takes the shape of its vessel and flows; water vapour has no shape at all and spreads through the whole space available. Evaporation is the change of water into water vapour. It goes on all the time, at every temperature — even at room temperature — and only from the surface . Boiling is different: it happens only at a fixed temperature, 100 °C for water, throughout the liquid, with bubbles. Condensation is the reverse change — water vapour turning back into liquid water. It happens whenever moist air touches a cold surface : droplets on a glass of cold water, dew on leaves, drops under the lid of a boiling pot. Heating and cooling change th
- Chapter opening
- Putting an ice cube in a cup
- .1 Investigating Water's Disappearing Act
- and 145A tablespoon of water on a steel plate (Fig. 8.1)
- Water sprinkled on a hot pan
- and 1478.2 Another Mystery
- and 1488.2 Another Mystery
- Humidity data for your area
- .3 What are the Different States of Water? (Table 8.3)
- and 1518.3 What are the Different States of Water?
Quick revision
| Term | What it means | Key value / everyday example | Where it comes in the chapter |
|---|---|---|---|
| States of water | The three forms of the same substance — solid, liquid and gas | Ice, water, water vapour | Activity 8.1 and Section 8.3, pages 144 and 150 |
| Water vapour | Water in its gaseous state; invisible, present in the air around us | Air in a room always contains some | Activity 8.2, page 145 |
| Steam | Water vapour in which some of the vapour has already turned into tiny droplets, which is why it is visible | The white cloud above a kettle | Page 145, Do you know? |
| Evaporation | The conversion of water into its vapour state, from the surface, at any temperature | Wet clothes drying; a mopped floor drying | Section 8.1, page 145 |
| Boiling | Rapid change into vapour from the whole liquid, at one fixed temperature | Water boils at 100 °C at sea level | Page 147 (boiling in a covered utensil) |
| Condensation | The conversion of water vapour into its liquid state | Droplets on a cold glass tumbler; dew | Section 8.2, page 148 |
| Melting | The conversion of a solid into the liquid state | Ice melts at 0 °C; candle wax melts | Section 8.4, page 152 |
| Freezing | The conversion of a liquid into the solid state | Water freezes at 0 °C in a freezer | Section 8.4, page 152 |
| Humidity | The amount of water vapour present in the air | High on a rainy day, low on a dry summer day | Pages 149 and 156 |
| Exposed area | The area of water in contact with air — larger area, faster evaporation | Water in a plate dries before water in a bottle cap | Activity 8.7, pages 153–154 |
| Cooling effect | The fall in temperature caused when water evaporates and takes heat away | Matka, surahi, sweat, sanitiser on the palm | Section 8.6, page 156 |
| Water cycle | The circulation of water between the Earth's surface and the atmosphere | Ocean → vapour → cloud → rain → river → ocean | Activity 8.11, page 159 |
Exercises
- Chapter opening — In-text Questions Page 143
- Putting an ice cube in a cup — Activity 8.1: Let us observe Page 144
- .1 Investigating Water's Disappearing Act — In-text Questions Page 1448
- and 145A tablespoon of water on a steel plate (Fig. 8.1) — Activity 8.2: Let us investigate Page 144
- .1 Investigating Water's Disappearing Act — In-text Questions Page 1458
- Water sprinkled on a hot pan — Let us draw Page 145
- and 1478.2 Another Mystery — Activity 8.3: Let us experiment Page 146
- and 1488.2 Another Mystery — In-text Questions Page 147
- and 149Weighing the condensation experiment on a digital balance — Activity 8.4: Let us measure Page 148
- Humidity data for your area — More to do! Page 149
- .3 What are the Different States of Water? (Table 8.3) — Activity 8.5: Let us identify Page 1508
- and 1518.3 What are the Different States of Water? — In-text Questions Page 150
- .4 How can we change the States of Water? — In-text Questions Page 1528
- Fig. 8.5 Conversion of different states of water — Activity 8.6: Let us complete the diagram Page 152
- .5 How can Water be Evaporated Faster or Slower? — In-text Questions Page 1538
- and 154Water in a bottle cap and water in a plate (Tables 8.4 and 8.5) — Activity 8.7: Let us investigate Page 153
- and 156Two bottle caps of water, one in sunlight and one in shade (Fig. 8.6) — Activity 8.8: Let us explore Page 155
- .6 Cooling Effect — In-text Questions Page 1568
- and 157A pot-in-pot cooler (Fig. 8.7) and the surahi (Fig. 8.8) — Activity 8.9: Let us make a model Page 156
- .7 How do Clouds give us Rain? — In-text Questions Page 1578
- Aavi's poem about the journey of water — In-text Question Page 158
- Making a cloud inside a plastic bottle — Activity 8.10: Let us engage in a group activity Page 158
- Fig. 8.9 Change of states and movement of water — Activity 8.11: Let us understand the process Page 159
- and 162Chapter exercises — Let us enhance our learning Page 161
- Extended activities and projects — Learning further Page 162