Evaporation: What Makes Water Dry Faster? — Answers
Answer sheet with model answers and success criteria for the Year 4 states of matter & materials worksheet.
Success TutoringWorksheetsAnswer sheetYear 4 · Science · States of Matter & MaterialsEvaporation: What Makes Water Dry Faster? — Answers
Part A: Where does the water go?
Read the passage. Then circle the best answer.
When liquid water turns into a gas, we call it evaporation. The gas is called water vapour. It is invisible and mixes into the air.
Evaporation happens all the time, even when water is not boiling. That is why puddles dry up and wet clothes dry when they are hung up.
Three things make water evaporate faster: warmth (heat from the Sun or a heater), wind (moving air carries the water vapour away) and a bigger surface area (spreading the water out so more of it touches the air).
Water evaporates more slowly when it is cool, the air is still, or the water is deep and in a narrow container.
- Aa gas turning into a liquid
- Ba liquid turning into a gas
- Ca liquid turning into a solid
- Da solid turning into a liquid
Answer: a liquid turning into a gas
In evaporation, a liquid such as water turns into a gas (water vapour).
- Adeeper into the cloth
- Binto the air as water vapour
- Cinto the ground only
- Dit disappears forever
Answer: into the air as water vapour
The water evaporates and becomes invisible water vapour in the air.
- Aa deep puddle in the shade on a cool, still day
- Ba shallow puddle in the sun on a warm, windy day
- Ca deep puddle in the sun on a still day
- Da shallow puddle in the shade on a cool day
Answer: a shallow puddle in the sun on a warm, windy day
Warmth, wind and a large, shallow surface all speed up evaporation.
- AMore of the water is open to the air.
- BIt gets heavier.
- CFolding adds water.
- DSpreading makes it colder.
Answer: More of the water is open to the air.
Spreading it out gives a bigger surface area, so more water can evaporate at once.
- Aa puddle drying up
- Ba wet floor drying
- Cice cream melting in the sun
- Dwater in a pot boiling away
Answer: ice cream melting in the sun
Melting is a solid turning into a liquid. The others are liquid water turning into water vapour.
Part B: Faster or slower?
- a shirt drying on a windy day
- a wet path in the sunshine
- water spilled over a wide tray
- warmth
- bigger surface area
- moving air
Answer: a shirt drying on a windy day → moving air; a wet path in the sunshine → warmth; water spilled over a wide tray → bigger surface area
Answer: vapour
Answer: wind
Answer: Hanging spreads the clothes out so more of the water touches the air, and the wind and warmth can reach it, so it evaporates faster.
Part C: True or false?
Write True or False.
Answer: False
Water evaporates at room temperature too; it just happens faster when it is warmer.
Answer: True
Warmth gives the water energy to change into a gas.
Answer: False
Some may soak in, but much of it evaporates into the air.
Answer: True
This is the change from liquid water to water vapour.
Part D: Working scientifically: the drying race
Use Noah's results to answer.
Noah soaked three cloths in the same amount of water and put them in different places. He checked every 5 minutes until each was dry.
Sunny windowsill: 25 minutes. Shady room: 45 minutes. Cool, dark cupboard: 80 minutes.
Answer: The cloth on the sunny windowsill (25 minutes).
Answer: The place where each cloth was put to dry (how warm and windy it was).
Answer: Any two of: the same size and type of cloth, the same amount of water, the same starting time, checking them the same way.
Model answer: The cloth in the warm, sunny place dried fastest and the cloth in the cool, dark cupboard dried slowest. Warmth makes water evaporate faster.
Success criteria:
- Uses the results to say which dried fastest and slowest
- Links warmth to faster evaporation
Marking tips
- Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
- For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
- Celebrate what went well first, then pick one thing to work on next.
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