Identifying Useful and Harmful Materials

The video provides a lesson for Grade 5 science students on identifying useful and harmful materials at home and in the environment. It explains the properties of useful materials, such as durability and reusability, and harmful materials, which can be corrosive or toxic. The video also discusses waste classification into biodegradable and non-biodegradable categories. An exercise is included to help students practice identifying materials, and a task is given to list examples of useful and harmful materials.

What is the main goal of this lesson?

• To identify useful and harmful materials

• To learn about the history of science

• To explore the solar system

• To understand the water cycle

Which property is NOT associated with useful materials?

• Durability

• Elasticity

• Flexibility

• Corrosiveness

Which of the following is an example of a useful material?

• Fruit peelings

• Car battery

• Bleach

• Medicine

What property is common in harmful materials?

• Elasticity

• Corrosiveness

• Flexibility

• Durability

Which of the following is considered a harmful material?

• Wood

• Fruit peelings

• Books

• Bleach

What type of waste can be decomposed by bacteria?

• Non-biodegradable

• Plastic

• Styrofoam

• Biodegradable

Which material is non-biodegradable?

• Fruit peelings

• Plastic

• Vegetable peelings

• Paper

Which of the following can be classified as a useful material?

• Old clothes

• Drain batteries

• Empty hair spray

• Used syringe

Which material is harmful if not disposed of properly?

• Disinfectant bottle

• Used paintbrush

• Plastic bottle

• Old newspaper

What should you do with materials that have served their primary use?

• Store them indefinitely

• Burn them

• Throw them in the ocean

• Recycle them