Physical and chemical change

• Scien
• Secondary Education
• Age 13

Physical and Chemical change

Learning Objective

Differentiate between chemical and physical changes.

 

Evaluate and list the characteristics of physical and chemical change.

LO: Differentiate between chemical and physical changes.

Evaluate and list the characteristics of physical and chemical change.

Let's answer

What kind of changes are  involved? 

What are the evidences of a physical change? 

Are all physical changes reversible? Give reason.

LO: Differentiate between chemical and physical changes.

Evaluate and list the characteristics of physical and chemical change.

• Group Activity :Analyse and observe the changes happened. Complete the task sheet provided.
• Activity 1: To Observe the sample of apple and potato provided. 
• Activity 2: Demonstration of the reaction between baking soda and vinegar
• Acticity 3: • Burning of Magnesium Ribbon: https://youtu.be/k6C2dETQ0bw

Characteristics of chemical change

No new product is formed

New product is formed

Evolution of gas

Generation of light and sound

Only physical properties like shape, size, colour etc. of the substance changes.

Generation of characteristic smell

Only chemical properties and composition of the substance changes.

Physical change

Chemical change

Create a Venn diagram to compare the characteristics of physical and chemical change.

Challenge Your Understanding 

1 .The liquified petroleum gas (LPG) is the gas which is used for cooking at home. In the cylinder, it comes as a liquid. When it comes out from the cylinder, it become a gas (Change A). Then it burns (Change B). Identify the changes and write the differences between changes A and B. 

2.  The toasted bread has undergone a chemical change because it cannot be converted to bread again (irreversible change). What does the toaster do? List the evidences for the changes that occurred.

3.  Evaluate the nature of the alloying process: should it be considered a physical change or a chemical change?

Extension/ HW

The Taj Mahal and the Great Wall of China are iconic monuments that have withstood the test of time, yet they are not immune to weathering and texture changes. Analyze the types of physical and chemical weathering processes affecting these monuments. How do these processes alter the texture and appearance of the structures over time? Propose strategies for preserving such historical monuments, considering both scientific and cultural factors.