Mixing It Up

Overview

Time: 30 minutes
Class Size: 30 pupils
Year Group: Year 4
Subject: Science
Curriculum Focus:

• National Curriculum Link: Science Key Stage 2 – Year 4 – States of Matter
  • Compare and group materials together, according to whether they are solids, liquids or gases
  • Observe that some materials change state when they are heated or cooled, and measure or research the temperature at which this happens in degrees Celsius (°C)
  • Identify the part played by evaporation and condensation in the water cycle and associate the rate of evaporation with temperature

Learning Objectives

By the end of this lesson, all pupils will be able to:

• Identify examples of solids, liquids, and gases
• Describe the properties of each state of matter
• Explain how substances can change state with heating or cooling
• Observe and record the results of a simple practical experiment involving a change of state

Differentiated Success Criteria

All learners will	Most learners will	Some learners will
Identify the three states of matter	Describe the difference between states of matter using simple scientific terms	Explain how heating or cooling causes changes of state using accurate scientific vocabulary
Contribute to the practical activity	Record observations and sort materials into the correct state of matter	Predict changes and explain scientific processes (e.g. evaporation) before and after the experiment

---

Resources Needed

• Laminated images or real objects representing solids, liquids, and gases (e.g. ice cube, water, balloon)
• Bowls (heatproof), teaspoons
• Chocolate buttons (or ice cubes depending on allergy/dietary needs) – one per group
• Kettles (pre-boiled and kept safely by adult)
• Stopwatch/timer
• Absorbent paper towels
• Whiteboards and markers
• Differentiated observation sheet (three levels)
• Safety goggles (optional but encouraged for engagement)

---

Vocabulary

• Solid
• Liquid
• Gas
• Melt
• Evaporate
• Condense
• Temperature
• State change

---

Starter (5 minutes) – 'Matter Mystery Box'

Activity: Pull three objects from a box:

• A small wooden block (solid)
• A sealed bottle half-full of water (liquid)
• A blown-up balloon (gas)

Ask pupils:

• What do you notice?
• Can you guess what connects these three items?
  Use ‘think-pair-share’ to discuss.

Bring the class together and introduce the concept: States of Matter.

---

Main Activity (20 minutes) – Melting Chocolate Investigation

Context: Pupils work in mixed-ability groups of 5. Each group receives a chocolate button in a bowl and places it near a warm surface (e.g. radiator) or under teacher-supervised hot water in a safe, controlled heat area.

Instructions:

1. Pupils observe the chocolate button before, during, and after melting.
2. Use a timer to measure how long it takes for the button to soften/melt.
3. Pupils record on their differentiated observation sheet:
   • What the chocolate looked like at the start
   • How long it took to change
   • What it looked like afterwards
   • Was it a physical or chemical change?

Differentiation Strategies:

Lower ability:

• Use visual prompts on observation sheet
• Adult/TA support with identifying descriptions
• Multiple choice guided vocabulary list

Middle ability:

• Scaffolded prompts on sheet (e.g. “At first, the chocolate was...”)
• Tick-box for properties (e.g. hard, soft, shiny)

Higher ability:

• Challenge question: What would happen if we left it overnight?
• Include prediction section before the experiment begins
• Extension task: Can you link this to what happens when water evaporates?

---

Plenary (5 minutes) – What’s the State?

Game: ‘Stand Up, Sit Down!’

• Teacher calls out materials (e.g. “steam”, “orange juice”, “rock”)
• Pupils stand for gas, crouch for liquid, sit for solid
  Quick-fire (10-12 terms), reinforcing learning in a high-energy, fun way.

Wrap-up:
Recap with the class:

• What’s one thing you learned today?
• What would happen to an ice lolly left in the sun?

---

Assessment Opportunities

• Observation of pupil responses during 'Matter Mystery Box'
• Group observations from the practical activity
• Answers and participation in ‘What’s the State?’ plenary game
• Differentiated observation sheets (used to inform future planning)

---

WOW Factor / Outside-the-Box

Science Surprise Element: Midway through the practical, the teacher (wearing a “Mad Scientist” hat or wig for drama) introduces a sealed zip bag with ice and asks pupils what would happen if we put it in the sun. Challenge pupils to start thinking about the water cycle and to visually observe condensation forming on the inside of the bag.

Pupils record this on a post-it and stick it to a display board titled:
"From Ice to Steam: Our States of Matter Journey"

---

Extension / Home Learning Suggestion

Melting Hunt: Ask pupils to observe at home what materials melt, freeze, or evaporate (e.g. butter on toast, condensation on windows). They can write or draw their findings to share in the next science lesson.

---

Health & Safety Notes

• Teacher to handle boiled water only.
• Keep any hot surfaces away from children’s reach.
• Ensure food allergies are checked before using chocolate.
• Clean hands before and after practical activity.

---

Reflection / CPD Prompt for Teachers

“Consider how using practical activities like this helps embed scientific concepts through exploration. How could you use similar activities to show reversible vs. irreversible changes later in KS2?”

---

End of Lesson

Reinforce key takeaways:

• Solids, liquids, and gases behave in different ways
• Heat can cause solids to melt or liquids to evaporate
• We can group materials by their state of matter

Encourage curiosity: “Next time, we’ll look at what happens inside a cloud!”

---

🌍 Science is full of everyday magic — let's help pupils see it first-hand!