Year 4 · Autumn 1.2 · Step 8

Earth & Space

Plan: an evaporation experiment

Planning a fair test — does the temperature of a place change how fast water evaporates?

Arrival Starter I do We do Independent Exit ticket

🌱 Seedling · Working towards 🌿 Sapling · Expected 🌳 Oak · Greater depth

⏱ Whole lesson ≈ 44 min · pick a tier in the bar, or leave on "All"

Arrival 4 min

Recap of last lesson: the water cycle.

Recap: evaporation

🌱 Seedling

Working towards

Evaporation is liquid turning to ____.

🌿 Sapling

Expected

Name the water cycle stages.
Does water need to boil to evaporate?

🌳 Oak

Greater depth

Where would a puddle dry up fastest — a fridge, a classroom or a radiator?

Bridge into todayWe'll plan another fair test: does the temperature of the place change how fast water evaporates?

Starter 5 min

Same water in three places; measured over hours, not seconds.

Planning the evaporation test

We put the same amount of water in shallow dishes in three places at different temperatures — a fridge, the classroom, and on a radiator — and check over hours to see where it evaporates fastest.

🌱 Seedling

Working towards

We change the ____ of the place.

🌿 Sapling

Expected

What do we change and what do we keep the same?

🌳 Oak

Greater depth

Why measure in hours, not seconds?

I do · 1 6 min

Teacher models the plan. Watch to recall evaporation.

What shall we change and keep the same?

▶ Can't see it? Watch "Evaporation — how heat turns water into vapour" on YouTube

Swap the clip: change the ID after /embed/ (now B77sebHmfdk).

Say thisWe change the temperature of the place, measure how much water is left over time, and keep the same the amount of water, the dish and the type of water. Warmer places should evaporate water faster.

🔧

Changethe place's temp

📏

Measurewater left

🟰

Keep samewater & dish

We do · 1 6 min

Predict and agree the plan together.

Predict and plan

Prediction: "The water will evaporate fastest ____, because it is the ____ place."

Agree the steps

Same water in each dish · place in fridge / classroom / radiator · check the level over hours · record what's left.

I do · 2 4 min

Play the animation. Show the fair-test setup.

Our evaporation test

Same water in three places — we change only the temperature and keep the water and dish the same.

Model the ideaOnly the temperature of the place changes. Using the same amount of water and the same dishes keeps it fair, so any difference must be down to temperature.

Watch for: thinking evaporation won't happen below 100°C — it happens at everyday temperatures too.

We do · 2 5 min

Change, measure or keep the same? Sort together.

Sort the plan

Decide together

"The temperature of the place." "How much water is left." "The amount of water we start with."

Change, measure, or keep the same?

Independent 10 min

On your own. Sort each part of the plan, then write at your tier.

Fair test sorter

🔧 We change it

📏 We measure it

🟰 We keep it the same

Tap a card to sort it…

🌱 Seedling

Working towards

Sort the cards. Then finish: We change the ____ of the place.

🌿 Sapling

Expected

Sort them, then write what we change, measure and keep the same.

🌳 Oak

Greater depth

Sort them, then explain why this makes a fair evaporation test.

Exit ticket 4 min

Answer at your tier, then hand it in.

Show what you know

🌱 Seedling

Working towards

What will we change?
What will we measure?

🌿 Sapling

Expected

Name two things we keep the same.
What is your prediction?

🌳 Oak

Greater depth

Explain what makes our evaporation test a fair test.