Skip to content Skip to navigation
Examples of physical change: a pan that is heated; tea that cools down
Examples of chemical change: burning match; toasting bread
Marshmallow
Leaner Section
People make use of different natural substances and change them into something else. To achieve this change, substances are mixed with other substances, heated, separated, dissolved or treated with electricity. Some changes are not permanent, while other changes cannot be reversed. We also distinguish between physical and chemical changes.
Physical Change
When crystallised honey is heated in a pot it becomes fluid again. But when it cools down and is exposed to air, it will crystallise once more. No new substances are formed and the properties of the honey remain exactly what they were. The change is a physical change. In the previous experiment, the orange/red mercuric oxide became black when it cooled down (physical change).
Chemical change
When you pour pancake batter into warm oil, something happens: the appearance of the batter changes. It is not runny any more, but stiff. The change that occurs is permanent. A change that is permanent and results in something new is a chemical change. The properties of the new substance differ from those of the original substances. The mercuric oxide also experienced a chemical change when it was decompounded into mercury and oxygen.
Name two further examples of physical and two examples of chemical change:
_____________________________________________________________________
______________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
Try the following:
Bring some marshmallows to school. Push them onto the prongs of a fork and heat them over a flame. Answer the questions that follow.
_____________________________________________________________________
______________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
 |
Learning Outcome 2:The learner will know and be able to interpret and apply scientific, technological and environmental knowledge.
Assessment Standard 2.3: We know this when the learner interprets information by identifying key ideas in text, finding patterns in recorded data, and making inferences from information in various forms (e.g. pictures, diagrams, text).
More about this module: Metadata | Downloads | Version History
This work is licensed by Siyavula Uploaders under a Creative Commons Attribution License (CC-BY 3.0), and is an Open Educational Resource.
Last edited by Siyavula Uploaders on Mar 16, 2009 2:49 am GMT-5.
