Checking progress account…

Lesson

Changes in Materials

Identify physical and chemical changes, and explain why reversibility alone is not a reliable test.

30min lesson

Objectives3 goals Lesson6 blocks Review11 assets Practice36 items

Learning objectives

What to understand

3 goals

Start lesson

Distinguish physical and chemical changes by whether new substances form.
Explain reversible changes using familiar examples.
Recognise why an irreversible change is not always chemical.

Lesson

Step-by-step lesson

6 sections

Concept

Key idea

A physical change alters a material's shape, size, state, or arrangement without making a new substance. Ice melting is physical: the solid and liquid are both water. Cutting paper is physical too, even though the original sheet is difficult to restore. A chemical change makes new substances. Iron reacts with oxygen and water to form rust. Burning paper forms substances such as gases and ash. These are chemical changes. A reversible change can be undone under suitable conditions. Melted ice can be frozen again. An irreversible change, in everyday classroom language, is one that cannot easily be undone to recover the original material. This does not mean that no laboratory process could ever change it again. Physical or chemical describes whether new substances form. Reversible or irreversible describes whether we can undo the change. These are different questions.

Ready to check what you remember?

Continue to revision

Study path

Choose your next activity

6 lesson sections6 cards / 5 notes19 MCQs / 17 written questions

Lesson Notes Flashcards Revision MCQs Written answers Topic test

Notes

Note highlights

5 notes

Review the compact notes before moving into recall.

Open notes

1
Key idea
2
Summary
3
Remember
4
Answer tip

Showing 4 of 5 notes.

Practice

Check this topic

36 prompts

19 MCQs17 LAQsMixed test

Choose one small set. The full bank opens only inside the practice session.

Start MCQs Write answers Topic test

In this chapter

Matter, Materials, and Mixtures

Topic 2 of 3

Now on Changes in Materials. Next up: Solutions and Separation.

Chapter Review Next

Lesson progress

Mark this topic complete

Not saved

Save this lesson when done. Next: Solutions and Separation.

Keep moving

Previous
Matter, Materials, and Mixtures
States and Properties of Matter
Previous
Next
Matter, Materials, and Mixtures
Solutions and Separation
Next

Opening your study space…

Changes in Materials

What to understand

Step-by-step lesson

Key idea

What to notice

Worked example

Common mistake to avoid

How to structure the answer

Quick check

Key idea

Choose your next activity

Note highlights

Key idea

Summary

Remember

Answer tip

Check this topic

Matter, Materials, and Mixtures

Mark this topic complete

Around this topic

Changes in Materials

What to understand

Step-by-step lesson

Key idea

What to notice

Worked example

Common mistake to avoid

How to structure the answer

Quick check

Key idea

Choose your next activity

Note highlights

Key idea

Summary

Remember

Answer tip

Check this topic

Matter, Materials, and Mixtures

Mark this topic complete

Around this topic