lesson
Some changes make different substances
1 · Learn
Burning and some chemical reactions form new materials. For example, a suitable acid reacting with bicarbonate of soda can produce a gas. These changes are not reversed simply by cooling or filtering.
Bubbles alone do not prove a new substance formed: boiling water also makes bubbles, but is a state change. Interpret observations using the substances, conditions and other evidence.
2 · Worked example
I compare an adult-described boiling example with an adult-demonstrated reaction. Both may bubble, so I do not identify the type of change from bubbles alone.
3 · Your turn
Does every bubbling liquid prove a chemical reaction forming new substances? Explain.
Check your answer
No. Boiling is a state change and can make bubbles too. More evidence about the materials and process is needed.
4 · Apply your learning
Use safe teacher-provided observations or video to compare reversible state changes with changes that form new substances. Record the evidence for each explanation.
Adult guidance and safety
No flames, sealed reaction containers, tasting or mixing household cleaners. Any reaction demonstration needs appropriate adult risk assessment and eye protection.
Open your writing and drawing pad
Write, draw or show your working. Use a mouse, pen or finger. This pad is not a submitted answer.
Not saved to your account. Download your drawing as PNG and your typed notes as TXT before leaving or refreshing. They are separate files. Do not enter private information.
Open a picture saved on this device to draw on it again. Opening replaces the drawing, but Undo can restore it. PNG only, up to 4 MB and 4096 × 4096 pixels. The picture stays in this browser; it is not uploaded. Paper lines in a saved picture become part of that picture.
Clear the drawing? Your typed notes will stay. You can undo this action.
Your pad is empty.
Open a UTF-8 TXT file from this device, up to 40 KB and 10,000 characters. It stays in this browser. Opening can be undone until you type again. Downloads keep a new copy; they do not change the file you opened.
Replace the notes on this page with the opened file? Download the current notes first if you want to keep them.
Typed notes are not submitted answers.
Check a calculation · Year 5 onward
Use this only when your teacher or adult allows a calculator for the task. Show your thinking first. It does not replace mental or written arithmetic and does not mark your lesson answer.
My observation notebook
With an adult, look at a safe real example or a checked photograph. Name the example and say which you used. Record what you actually notice. Do not taste plants or materials, approach unknown animals or invent missing observations.
Ask your teacher for support with the method and recording. A prediction is what you think might happen; an observation is what you actually see, hear or feel safely.
Keep your notebook: use Download notebook before leaving. Nothing is sent to the website or saved to your account. Reopen the downloaded notebook here to add another day's record. Do not include names, addresses or other private information.
Your records on this page
No observations recorded yet. Look first, then add one.
Reopening adds records; it does not replace your current records. Up to 50 records per notebook. Keep your downloads somewhere private. Editing this notebook does not submit work or complete a lesson.
Practice this lesson
Lesson resources
Browse the available practice activities and worksheets for this lesson.
Your progress