Introduction to physical and chemical changes :
Physical and chemical changes are fundamental concepts that every student should understand. In this lesson, students will be able to differentiate between physical and chemical changes through a hands-on demonstration and interactive activities.
Demonstration of physical and chemical changes:
Start the lesson by lighting a candle and allowing it to melt. Ask the students to observe what is happening and to take verbal responses to improve concepts of physical and chemical changes
. Collect the candle wax formed. Then, light a matchstick and let it burn until it changes into ash. Collect the ash of the matchstick.
Explanation of physical and chemical changes:
Explain to the students that the first demonstration showed a solid candle changing into liquid wax, which is a physical change. This type of change only consists of a change in state and no new substance is created.
Next, explain that the second demonstration showed the matchstick changing into ashes and smoke, which is a chemical change. Two new substances were created, and it is not possible to reverse a chemical change.
Interactive Activity of
physical and chemical changes:
Display a list of changes or an image of the list on the board. Ask the students to make columns in their notebooks: Changes, Physical change, Chemical change. Then, read each change out loud and ask the students to show a thumbs up if the change is physical, and a thumbs down if the change is chemical. Finally, ask the students to place a check in the correct column in their notebooks.
Here is the list of changes:
- Ice melting is a physical change
- Cutting a pineapple is a physical change
- Adding vinegar to soda is a chemical change
- A piece of rusting metal is a chemical change
- Campfire is a chemical change
- Crumbling a piece of paper is a physical change
- Sour milk is a chemical change
- Shattering a drinking glass is a physical change
- Dissolving sugar in water is a physical change
- Burning paper is a chemical change
- Boiling water is a physical change
- Burning a match is a chemical change
Conclusion of physical and chemical changes:
In conclusion, this lesson allows students to understand the difference between physical and chemical changes and to differentiate between them through hands-on demonstrations and interactive activities. It also helps students understand that some changes are irreversible and others can be changed back to their original state. This is a fun and educational way to teach this important concept.”
