You will learn
- Define matter and mass.
- Measure mass.
- Show conservation of mass.
- Distinguish mass and weight in simple terms.
Version 0.2 · expanded edition · built from cited public sources Content is based on the official frameworks and sources listed under Sources and standards. No official endorsement is claimed. Written in the style of common primary school assessments. No exam result is promised.
Student lesson
- All matter has mass and volume.
- Mass is measured in grams and kilograms.
- Mass is conserved when matter changes form.
- Air is matter.
Words to know
anything with mass that takes up space
the amount of matter in an object
the space an object takes up
a tool that measures mass
1. Discover: The melting ice cube
Adwoa weighs a sealed bag with an ice cube: 85 grams. When the ice melts inside the sealed bag she weighs it again: still 85 grams. “The ice became water but the mass stayed the same,” she says.
Think: Why did the mass not change?
2. Understand: Matter
Idea 1: What is matter
Matter is anything that has mass and takes up space (volume). Solids, liquids and gases are all matter, even air.
Idea 2: Measuring
Mass is measured with a balance in grams (g) or kilograms (kg). Volume is measured in millilitres (ml) or cubic centimetres (cm³).
Idea 3: Conservation
When matter changes state or dissolves in a closed system, the total mass stays the same. Nothing is lost; the particles are just arranged differently.
3. Worked examples
Example 1 (I show you): Decide
Air.
- Takes space.
- Has mass.
- Matter.
Answer: Air is matter.
Example 2 (We do it together): Decide
Light.
- No mass.
- No volume.
- Not matter.
Answer: Light is not matter.
Example 3 (You try): Predict
Melting in bag.
Show the steps and answer
- Sealed.
- Same mass.
- Conserved.
Answer: Mass stays the same.
Did you know?
A litre of air at sea level has a mass of about 1.2 grams.
Why this matters
Knowing that mass is conserved helps scientists track substances.
4. Explore: Mass check
Weigh a sealed bag of ice before and after melting and weigh a balloon before and after inflating it.
- Weigh bag with ice.
- Wait to melt.
- Weigh again.
- Weigh an inflated balloon.
Think about it: what did you notice?
What did you notice? Melted water had the same mass; air added mass to the balloon.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- ___ has mass and takes up space.
- ___ is the amount of matter.
- ___ is the space an object takes up.
- A ___ measures mass.
Guided practice
Question 1. What is matter?
Mass and space.
Question 2. What is mass?
Amount of matter.
Question 3. What is volume?
Space taken.
Independent practice
Level 1: Start
- What is matter?
- What is mass?
- What is volume?
- What measures mass?
- What unit?
Level 2: Grow
- Why conserved?
- Why sealed bag?
- Why is air matter?
Level 3: Stretch
- Weigh the bags.
- Weigh the balloon.
- Explain.
Answers are in the answer key below. Try first, then check.
6. Apply: Science in everyday life
Explain why mass stays the same when ice melts in a sealed bag.
Show a sample answer
Use particles.
Another one. Tell a family member one thing from this lesson. Use the words you learned.
Show a sample answer
A clear sentence that uses at least one word from Words to know.
7. Common mistakes
Fix: Air is matter.
Fix: Mass is conserved.
8. Lesson summary and revision card
- I can define matter and mass.
- I can measure mass.
- I can show conservation of mass.
- I can distinguish mass and weight in simple terms.
9. Check and master
Answer all 14 questions. You will see feedback after each one.
Your result appears here after you answer every question.
10. Key takeaways
- All matter has mass and volume.
- Mass is measured in grams and kilograms.
- Mass is conserved when matter changes form.
- Air is matter.
11. Next lesson
Next lesson: Properties of matter. Keep going with the next idea in this course.
Exam practice
These questions are written in the style of common school and international primary assessments. Try them on your own, without looking back. Then check your answers in the marking guide. The marks are shown in brackets.
- Define matter and mass. [2 marks]
- Sort four things as matter or not. [4 marks]
- Explain conservation of mass. [2 marks]
- Safety rule. [2 marks]
Total: 10 marks.
Marking guide and model answers
- 1 each
- 1 each
- Same mass [1]; reason [1]
- Any [1]; reason [1]
Score guide: 9 to 10 = secure. 6 to 8 = nearly there, revise the parts you missed. Under 6 = work through the lesson again with a grown-up.
Printable worksheet
- What is matter?
- What is mass?
- What is volume?
- What measures mass?
- What unit?
- Why conserved?
- Why sealed bag?
- Why is air matter?
- Weigh the bags.
- Weigh the balloon.
Homework
Find five examples of matter and one non-matter at home.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 1. What is matter? | Mass and space. | 1 |
| 2. What is mass? | Amount of matter. | 1 |
| 3. What is volume? | Space taken. | 1 |
| 4. What measures mass? | Balance. | 1 |
| 5. What unit? | Grams. | 1 |
| 6. Why conserved? | Same particles. | 1 |
| 7. Why sealed bag? | Nothing escapes. | 1 |
| 8. Why is air matter? | Has mass. | 1 |
| 9. Weigh the bags. | Table. | 1 |
| 10. Weigh the balloon. | Table. | 1 |
| Total | 10 |
Independent practice answers. Level 1: 1 Mass and space.; 2 Amount of matter.; 3 Space taken.; 4 Balance.; 5 Grams.. Level 2: 1 Same particles.; 2 Nothing escapes.; 3 Has mass.. Level 3: 1 Table.; 2 Table.; 3 Sentence..
Quiz answers: 1 B, 2 C, 3 A, 4 B, 5 C, 6 A, 7 B, 8 C, 9 A, 10 B, 11 C, 12 A, Challenge 1 B, Challenge 2 C.
Mastery and remediation
| Objective | Bronze (Developing) | Silver (Proficient) | Gold (Advanced) |
|---|---|---|---|
| O1 Define matter and mass | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O2 Measure mass | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O3 Show conservation of mass | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O4 Distinguish mass and weight in simple terms | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
Courseversity badge thresholds (overall quiz score): Gold = 90–100%; Silver = 80–89.9%; Bronze = 70–79.9%. A badge is never a full record of progress.
If a learner struggles
- Find the misconception: “Air is nothing.” Air is matter.
- Explain another way: use real objects, pictures or actions first, then words.
- Show a simpler example: Explain matter and mass.
- Guided practice: work through one example together and let the learner try the next one.
- Reassess: use the quiz again or the worksheet.
- Move on when the learner shows Silver-level evidence independently.
For parents and guardians
In this lesson your child weighs matter. You do not need to be an expert to help.
- Weigh food items.
- Ask “Is it matter?”
- Wipe spills.
- Ask “how do you know?” after each answer, and listen.
- Praise effort, not only right answers. Mistakes are how we learn.
- Ten to fifteen minutes a day is better than one long session.
Teacher package
1–5. Objectives, prerequisites, materials, preparation, duration
Lesson objectives. Learners will: define matter and mass; measure mass; show conservation of mass; distinguish mass and weight in simple terms.
Prerequisite knowledge. Grade 4 ideas: properties of materials, states of matter, melting, freezing, evaporation, dissolving and reversible changes.
Materials. Balance, bags, ice. Low-resource options: use chalk or charcoal on a board or wall, drawings in the sand, and objects from the classroom instead of printed materials.
Preparation. Chill ice.
Suggested duration. 45–60 minutes. It can be split into two shorter sessions.
6–9. Teaching procedure, explanation notes, guided and independent activities
Introduction (5 min). Weigh a balloon before and after inflating and ask, “What changed?”
Explanation (10 min). Teach matter.
Guided activity (10 min). Learners weigh.
Independent activity (10 min). Learners explain.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. Does it have mass? Space?
Teacher explanation notes. Start with real objects and safe, hands-on observation. Then talk about what was seen, then draw and write. Always say “how do you know?”. Keep to the safety notes, and use local, safe materials.
10–12. Differentiation, formative assessment, common misconceptions
Support. Use real objects and pictures, short sentences and a partner. Let learners point, show or draw instead of writing. Extension. Ask learners to find a new example at home and explain how they know.
Formative assessment. Listen to learners read and explain, ask “how do you know?”, and check the independent work.
Misconceptions. “Air is nothing.” Air is matter.
13–15. Assessment questions, answer keys, marking scheme
Use the quiz, the 10-mark exam practice and the worksheet on this page. All answers and marking guides are in the answer sections above. Re-check every answer before use.
16–19. Remediation, enrichment, homework, teacher reflection
Remediation. Explain matter and mass. Enrichment. Look for one new example near your home or school, draw it and explain it to someone. Homework. See above.
Teacher reflection. After teaching, record: which ideas learners understood; which misconceptions occurred; which activities worked; which learners need more practice; and what to improve next time.
Sources and standards
This lesson is based on the sources below, and no official endorsement is claimed. Reference starting points: Next Generation Science Standards, Cambridge Primary Science and the IB Primary Years Programme. Where a standard code is named, it points to the official framework.
Research used to shape this lesson. Courseversity Science curriculum, Grade 5 Unit 4, topic 1; Next Generation Science Standards, structure and properties of matter; Cambridge Primary Science Stage 5, chemistry: states of matter and materials; IB Primary Years Programme, how the world works. These sources informed the lesson.