Samacheer Kalvi Class 4 Science Solutions Term 3 Chapter 1 Green Environment

I. Choose the Correct Answer:

Question 1. What is the first step in waste management?
(a) Waste disposal
(b) Waste separation
(c) Waste collection
Answer: (b) Waste separation
In simple words: The first important step to manage waste is to sort it into different types before any other process.

🎯 Exam Tip: Understanding the correct sequence of waste management steps is crucial for environmental studies.

Question 2. Which is an example for non-biodegradable waste?
(a) Paper cup
(b) Plastic cup
(c) Coconut shell
Answer: (b) Plastic cup
In simple words: A plastic cup cannot break down naturally into the soil over time, unlike paper or coconut shells.

🎯 Exam Tip: Remember that non-biodegradable items stay in the environment for a very long time, causing pollution.

Question 3. Picking up the waste is called __________
(a) Waste collection
(b) The environment
(c) Litter
Answer: (a) Waste collection
In simple words: When we gather up trash from different places, it is correctly named waste collection.

🎯 Exam Tip: Waste collection is the process of gathering discarded items from various sources.

Question 4. __________ is the first 'R' in the Three R's.
(a) Reuse
(b) Reduce
(c) Recycle
Answer: (b) Reduce
In simple words: The first and most important step in the Three R's is to reduce the amount of waste we create in the first place.

🎯 Exam Tip: Always remember the order of the Three R's: Reduce, Reuse, Recycle, as 'Reduce' is the most impactful.

II. Fill in the Blanks:

Question 1. __________ is an example of reusing waste.
Answer: Using old jars for pickle. Using items for a new purpose instead of throwing them away is an excellent way to reuse.
In simple words: Reusing means finding another use for something, like keeping old jars to store pickles.

🎯 Exam Tip: Provide clear examples of reuse, focusing on giving an item a second life in its original or a modified form.

Question 2. __________ is used to make bags, dustbins and tooth brushes.
Answer: Bamboo. Bamboo is a strong and fast-growing plant that is often used to create many sustainable products.
In simple words: Bamboo is a natural material used to make things like bags, dustbins, and toothbrushes.

🎯 Exam Tip: When filling in blanks, choose the option that best fits the context and provides a correct factual statement.

Question 3. __________ is a big threat to our environment.
Answer: Plastic pollution. This type of pollution harms animals and ecosystems because plastics break down very slowly.
In simple words: Plastic pollution causes great harm to our environment and nature.

🎯 Exam Tip: Understand the different types of pollution and their specific impacts on the environment.

Question 4. __________ is a non-recyclable item.
Answer: Multilayer plastics. These plastics are made of different layers and are very hard to separate and process for recycling.
In simple words: Multilayer plastics are items that cannot be easily recycled into new things.

🎯 Exam Tip: Differentiate between recyclable and non-recyclable items; multilayer plastics are a common example of non-recyclable waste.

III. Match the Following:

Question 1. Match the following:
1. Plastics waste - Threat to environment
2. Waste separation - Biodegradable, recyclable and non-recyclable
3. Reduce, Reuse and Recycle - Three R's
4. Stainless steel - Eco-friendly material
Answer:
1. Plastics waste - Threat to environment
2. Waste separation - Biodegradable, recyclable and non-recyclable
3. Reduce, Reuse and Recycle - Three R's
4. Stainless steel - Eco-friendly material
In simple words: This match shows how different items and actions relate to waste and the environment. For example, plastic waste harms the environment, and the 'Three R's' are a method to manage waste.

🎯 Exam Tip: For matching questions, carefully read both columns to find the most appropriate and correct pairs. Double-check all connections.

IV. Write True or False:

Question 1. 3R method reduces the amount of waste that goes to landfills.
Answer: True. The 3R method (Reduce, Reuse, Recycle) aims to lessen the total amount of trash needing disposal.
In simple words: Yes, using the 3R method helps to make less garbage that ends up in big dump sites.

🎯 Exam Tip: Remember that 'Reduce' is the most effective part of the 3R method in minimizing waste to landfills.

Question 2. Eco-friendly material is harmful to the environment.
Answer: False. Eco-friendly materials are designed to be safe and helpful for the environment.
In simple words: This is not true. Eco-friendly materials are actually good for the environment, not harmful.

🎯 Exam Tip: Understand the definition of 'eco-friendly' materials as those that do not harm the environment.

Question 3. Plastic bag, thermocol and multilayer plastics are recyclable.
Answer: False. Many plastic bags, thermocol, and multilayer plastics are difficult to recycle or are non-recyclable.
In simple words: No, this is wrong. Many plastic bags, thermocol, and multilayer plastics cannot be recycled.

🎯 Exam Tip: Be aware that not all plastic items are easily recyclable; some types pose significant challenges.

Question 4. We should conserve our natural resources and energy
Answer: True. Conserving resources and energy is vital for a healthy planet and for future generations.
In simple words: Yes, it is very important to save our natural resources and energy.

🎯 Exam Tip: Conservation means protecting and preserving natural resources and energy for sustainable use.

V. Answer in One or Two Sentences:

Question 1. What are the Three R's?
Answer: The Three R's are a set of principles for managing waste, standing for Reduce, Reuse, and Recycle. Following these helps protect the environment.
In simple words: The Three R's are Reduce, Reuse, and Recycle, which help us deal with waste.

🎯 Exam Tip: List all three R's clearly and accurately to score full marks for this foundational concept.

Question 2. What is bio-degradable waste?
Answer: Biodegradable waste is trash that comes from plants or animals and can be broken down naturally by living organisms. For example, food scraps and garden waste are biodegradable.
In simple words: Biodegradable waste is natural trash, like food, that can rot away and mix back into the earth.

🎯 Exam Tip: Clearly define biodegradable waste as natural materials that can be broken down by microorganisms.

Question 3. Write the different steps in waste management.
Answer: The main steps in waste management include:
• Separation of waste
• Waste collection and transportation
• Waste recycling and composting
• Waste disposal. Each step is important for handling trash responsibly.
In simple words: First, we sort waste, then collect it, then try to recycle or compost it, and finally, get rid of what's left.

🎯 Exam Tip: List the waste management steps in their logical order, from separation to final disposal.

Question 4. Name five items which are recyclable.
Answer: Five common recyclable items are paper, glass, metal, cardboard, and certain plastic covers. Recycling these helps create new products.
In simple words: Things like paper, glass, metal, cardboard, and some plastics can be recycled.

🎯 Exam Tip: Provide diverse examples of recyclable materials, covering different categories of waste.

VI. Answer the Following:

Question 1. How will you manage the household waste?
Answer: To manage household waste well, we should:
• Divide the waste into different bins.
• Make sure each bin holds a specific type of waste.
• Use a green bin for biodegradable waste, a blue bin for recyclable waste, and a red bin for non-recyclable waste. This system helps in proper disposal and recycling.
In simple words: We can manage house waste by sorting it into different colored bins: green for natural waste, blue for things that can be recycled, and red for other trash.

🎯 Exam Tip: Describe a clear and practical method for household waste segregation, mentioning the typical color-coding for bins.

Question 2. What are the plastic items that have been banned in Tamil Nadu?
Answer: In Tamil Nadu, several plastic items have been banned, including plastic bags, plastic plates, water pouches, plastic straws, and plastic sheets. This ban helps reduce plastic pollution.
In simple words: Tamil Nadu has stopped the use of many plastic items like bags, plates, water pouches, straws, and sheets to protect the environment.

🎯 Exam Tip: Name specific banned plastic items accurately, showing awareness of local environmental policies.

Question 3. Write the benefits of recycling.
Answer: Recycling offers many benefits:
• Old newspapers, notebooks, and magazines can be sold to a scrap dealer and then turned into new paper.
• PET bottles are recycled into plastic threads, which are then used to make things like sports T-shirts.
• Old glass bottles and broken glass pieces are melted down to create new glass products.
• Broken metal items, such as tiffin boxes and plates, are melted and reshaped into new metal products like toys. Recycling saves resources and energy.
In simple words: Recycling turns old things like paper, plastic bottles, glass, and metal into new products, saving materials and helping the environment.

🎯 Exam Tip: Explain the benefits of recycling by giving specific examples of how different materials are transformed into new useful items.

Question 4. What is known as eco-friendly material?
Answer: Eco-friendly materials are those that are good for the environment and do not cause any harm to it. These materials often help reduce pollution and save natural resources.
In simple words: Eco-friendly materials are things that are helpful for nature and do not hurt the environment.

🎯 Exam Tip: Define eco-friendly materials by highlighting their positive impact and lack of harm to the environment.

Samacheer Kalvi 4th Science Guide Green Environment In Text Questions and Answers

Activity (Text Book Page No. 65)

Question 1. Write the waste management process in the correct order.
Answer: The correct order of waste management processes is:
1. Waste separation
2. Waste collection & transportation
3. Waste recycling & composting
4. Waste disposal. Following these steps helps manage waste effectively.
In simple words: First, we separate waste, then collect and move it, after that we recycle or compost it, and finally, we dispose of what is left.

🎯 Exam Tip: Remember the logical sequence of waste management steps to correctly order them for such questions.

Activity (Text Book Page No. 67)

Question 1. List out four things that you can reduce, reuse and recycle at home or school.
Answer: Here are four ways to reduce, reuse, and recycle at home or school:
Reduce:
• Use of plastic carry bags
• Buy food in bulk & avoid plastic bags
• Buy a refill instead of a pen
• Turn off lights and fans when you leave a room
Reuse:
• Old clothes to clean home & cycle
• Use jam & pickle jars to store things
• Clothes that look good can be donated to poor
• Reuse waste & make something new
Recycle:
• Old newspapers, notebooks, magazines
• Old glass bottles to make new bottles
• Broken metal items to make toys
• Pet bottles to make plastic thread
In simple words: We can reduce how much we use, find new uses for old items, and send materials for recycling to help the environment at home and school. This list provides specific examples for each 'R'.

🎯 Exam Tip: When listing examples for Reduce, Reuse, and Recycle, try to provide distinct and clear actions for each category.

Activity (Text Book Page No. 70)

Question 1. Study the images below and write down three items you have at home in each category of waste.
Answer:
• Biodegradable items commonly found at home include vegetable peels, fruit peels, and mats.
• Recyclable items include glass, metal, paper, and cardboards.
• Non-recyclable items consist of plastic bags, CFL lights, and mixed electronic wastes. Understanding these categories helps with proper waste segregation.
In simple words: We can find different kinds of waste at home: things that rot (like fruit peels), things that can be recycled (like glass), and things that cannot be recycled (like some plastics and old lights).

🎯 Exam Tip: Categorize waste correctly into biodegradable, recyclable, and non-recyclable for effective home waste management.

Samacheer Kalvi 4th Science Guide Green Environment Additional Questions and Answers

I. Choose the Correct Answers:

Question 1. Unwanted materials pollute our __________
(a) Land
(b) Air
(c) Both (a) and (b)
Answer: (c) Both (a) and (b)
In simple words: Trash and harmful things can make both the land and the air dirty.

🎯 Exam Tip: Remember that pollution affects various parts of our environment, including land and air.

Question 2. __________ is the very important step in waste management.
(a) Separation of waste
(b) Waste disposal
(c) Waste collection
Answer: (a) Separation of waste
In simple words: Sorting waste is the most crucial first step to manage it properly.

🎯 Exam Tip: Emphasize segregation as the foundational step for effective waste management and recycling.

Question 3. __________ is to take materials from things you throw away and make new products with them.
(a) Reduce
(b) Reuse
(c) Recycle
Answer: (c) Recycle
In simple words: Recycling means taking old items and turning them into new ones instead of throwing them away.

🎯 Exam Tip: Distinguish clearly between 'reduce', 'reuse', and 'recycle' by their definitions and actions involved.

Question 4. __________ can return back to the soil and become food for plants.
(a) Biodegradable
(b) Non-degradable
(c) Recyclable
(d) None of the options
Answer: (a) Biodegradable
In simple words: Things that are biodegradable can naturally break down and enrich the soil for plants.

🎯 Exam Tip: Remember that biodegradable materials naturally decompose and are important for soil health.

Question 5. __________ is an example for eco-friendly material.
(a) Leaf plate
(b) Plastic plate
(c) Thermocol plate
Answer: (a) Leaf plate
In simple words: A leaf plate is a good example of an eco-friendly material because it is natural and breaks down easily without harming the earth.

🎯 Exam Tip: Identify materials that are natural and decompose easily as examples of eco-friendly options.

II. Fill in the Blanks:

Question 1. Picking up the waste is called __________
Answer: Waste collection. This is the process of gathering discarded items from various sources.
In simple words: When trash is gathered, it is called waste collection.

🎯 Exam Tip: Choose the term that accurately describes the action of gathering waste materials.

Question 2. __________ waste can be turned into something new which is valuable.
Answer: Recyclable. This type of waste can be processed and transformed into new useful products, adding value to old materials.
In simple words: Trash that can be recycled can be made into new, useful things.

🎯 Exam Tip: Understand that recyclable waste has the potential to be remade into new items, preventing waste.

Question 3. __________ is using something repeatedly for the same or for another purpose.
Answer: Reuse. This means to use an item again and again, either for its original job or a different one, instead of throwing it away.
In simple words: Reuse means to use something more than once for the same purpose or a new purpose.

🎯 Exam Tip: Remember that 'reuse' extends the life of a product, reducing the need for new items.

Question 4. __________ of our environment means to protect all things found in nature.
Answer: Conservation. This involves carefully managing and protecting natural resources and wildlife to ensure their survival and health for future generations.
In simple words: Conservation means taking care of and protecting everything natural in our environment.

🎯 Exam Tip: Define conservation as the protection of natural things, distinguishing it from simple observation.

Question 5. Plastic bags and food packaging is a __________ item.
Answer: Non-recyclable. Many plastic bags and types of food packaging cannot be easily recycled due to their material composition or contamination.
In simple words: Most plastic bags and food packaging are not recyclable and should be thrown away in the non-recyclable bin.

🎯 Exam Tip: Remember that not all plastics are recyclable; many bags and food packaging types fall into the non-recyclable category.

III. True or False:

Question 1. It is best to separate waste into 3 different bins.
Answer: True. Separating waste into categories like biodegradable, recyclable, and non-recyclable helps in effective processing.
In simple words: Yes, it is a good idea to sort trash into three separate bins for proper handling.

🎯 Exam Tip: Emphasize the importance of waste segregation into multiple categories for better management.

Question 2. Reuse is to make or use less
Answer: False. 'Reduce' means to make or use less, while 'reuse' means to use an item again for the same or a new purpose.
In simple words: This is wrong. 'Reuse' means to use something again, but 'reduce' means to use less of it.

🎯 Exam Tip: Clearly differentiate between the definitions of 'reduce' and 'reuse' in waste management principles.

Question 3. Broken glass pieces are melted to make new glass.
Answer: True. Melting broken glass is a common recycling process to produce new glass products, saving raw materials and energy.
In simple words: Yes, old broken glass can be melted down to create new glass items.

🎯 Exam Tip: Understand that glass is highly recyclable and can be repeatedly melted and reformed without losing quality.

Question 4. We should conserve our natural resources and energy
Answer: True. Conserving natural resources and energy is crucial for environmental sustainability and to ensure availability for future generations.
In simple words: Yes, it is very important to save our natural resources and energy so they don't run out.

🎯 Exam Tip: Recognize conservation as a key practice for protecting the environment and ensuring sustainable living.

IV. Answer the Following:

Question 1. What is separation of waste?
Answer: Separation of waste means sorting or dividing trash into different types and placing them into appropriate bins. This step is essential for effective recycling and disposal.
In simple words: Separating waste means putting different kinds of trash into different bins.

🎯 Exam Tip: Define waste separation clearly, emphasizing its role in classifying waste for proper handling.

Question 2. What is waste collection?
Answer: Waste collection is the process where our local municipality or corporation gathers discarded items from homes and public places. This helps keep our surroundings clean.
In simple words: Waste collection is when the city picks up trash from our homes and streets.

🎯 Exam Tip: Explain waste collection as the systematic gathering of waste, often by local authorities.

Question 3. What is transportation?
Answer: Transportation, in the context of waste management, means moving the collected waste from one location to another. This often involves moving it to recycling centers, composting sites, or landfills.
In simple words: Transportation is moving trash from one place to another, like to a dump or recycling center.

🎯 Exam Tip: Define waste transportation as the movement of waste from collection points to processing or disposal sites.

Question 4. What is compost?
Answer: Compost is a rich, dark organic material formed when biodegradable waste breaks down naturally. This material is very good for plants and helps make the soil fertile, providing nutrients.
In simple words: Compost is rotted plant and food waste that makes soil healthy and helps plants grow better.

🎯 Exam Tip: Explain compost as decayed organic matter that enriches soil, highlighting its origin from biodegradable waste.

Question 5. What is waste disposal or final disposal?
Answer: Waste disposal, also known as final disposal, refers to the process of sending waste that cannot be recycled or reused to its final resting place, usually a landfill. This is the last step in waste management.
In simple words: Waste disposal is when trash that cannot be recycled or used again is sent away to a final dump site.

🎯 Exam Tip: Define final disposal as the last step for non-recyclable waste, typically involving landfills.

Question 6. What is Reduce?
Answer: Reduce means lessening the amount of materials we consume or use. This is the most effective way to manage waste as it prevents waste from being created in the first place.
In simple words: Reduce means to use or make less of something.

🎯 Exam Tip: Emphasize 'reduce' as the primary and most impactful step in the Three R's, as it minimizes waste generation.

Question 7. What is Reuse?
Answer: Reuse is the act of using an item again and again for its original purpose or for a completely different one. This extends the item's life and reduces waste.
In simple words: Reuse means using something many times, either for what it was made for or for a new purpose.

🎯 Exam Tip: Define reuse as giving an item a second life, whether for its original use or a new creative application.

Question 8. What is Recycle?
Answer: Recycle means collecting discarded materials, processing them, and then turning them into new products. This helps save natural resources and energy.
In simple words: Recycle means taking old items, changing them, and making new items out of them.

🎯 Exam Tip: Clearly define recycle as transforming old materials into new products, highlighting its resource-saving benefit.

Question 9. Name some materials that you can at home recycle?
Answer: Materials you can often recycle at home include PET bottles, old glass bottles and broken glass pieces, and broken metal items. These can be collected for proper recycling.
In simple words: At home, we can recycle things like plastic bottles, old glass, and broken metal pieces.

🎯 Exam Tip: List common household items that are widely accepted for recycling programs.

V. Answer in Detail:

Question 1. Write down the eco-friendly activities.
Answer: Here are some important eco-friendly activities:
• Reduce your paper use by writing on both sides of every sheet.
• Stop using single-use plastic straws.
• Always use reusable bags when shopping.
• Avoid chewing gum, as it's often non-biodegradable.
• Choose to buy stainless steel bottles instead of plastic water bottles.
• Reuse containers to store leftover food or other items. These actions help protect our planet.
In simple words: To be eco-friendly, we should use less paper, avoid plastic straws, use reusable bags and bottles, and reuse containers.

🎯 Exam Tip: Provide a diverse list of practical eco-friendly actions, covering different aspects of daily life.

Question 2. What is meant by conservation of environment?
Answer: Conservation of the environment means taking steps to protect all the natural elements and living things found in nature. It involves using our Earth's natural resources, such as water, soil, minerals, wildlife, and forests, in a very careful and responsible way. Everyone can contribute to environmental conservation by adopting good waste management habits and making conscious choices to protect resources.
In simple words: Conservation of the environment means taking care of nature, using Earth's resources carefully, and managing our waste well to protect everything for the future.

🎯 Exam Tip: Explain environmental conservation by covering both the protection of nature and the careful use of natural resources.

Question 8. What is Recycle?
Answer: Recycling means collecting old, used items and changing them into new things. This process helps save natural resources and reduces the amount of waste that goes to landfills.
In simple words: Recycling turns old trash into new products.

🎯 Exam Tip: Clearly define recycling by mentioning both collecting old materials and converting them into new products.

Question 9. Name some materials that you can at home recycle?
Answer: Some items you can recycle at home include:

• PET bottles (like plastic water bottles).
• Old glass bottles and broken glass pieces.
• Broken metal items, such as old cans or parts.

🎯 Exam Tip: Provide specific examples of common household items that can be recycled to show a practical understanding.

V. Answer in Detail:

Question 1. Write down the eco-friendly activities.
Answer: Here are some actions that are good for the environment:

• Use less paper by writing on both sides of each sheet.
• Do not use plastic straws, opting for reusable alternatives.
• Carry and use a bag that can be used many times instead of single-use plastic bags.
• Avoid chewing gum, as it creates sticky waste that is hard to dispose of.
• Choose steel bottles over plastic water bottles for drinking.
• Reuse old containers for storing leftover food or other items.

🎯 Exam Tip: When listing activities, choose a variety of actions that cover different aspects of daily life to show a broad understanding of eco-friendliness.

Question 2. What is meant by conservation of environment?
Answer: Protecting the environment means taking care of everything in nature. This includes using Earth's natural resources, like water, soil, minerals, wildlife, and forests, in a wise and careful way. Good waste management habits also help everyone protect the environment. It is about making sure these resources are available for the future.

• Conservation of environment means to protect all things found in nature.
• It means that we have to use our Earth's natural resources (like water, soil, minerals, wildlife and forests) carefully.
• Everyone can conserve the environment by good waste management habits.

🎯 Exam Tip: Explain conservation by mentioning both protecting nature and using resources wisely, and also include the role of waste management.