Samacheer Kalvi Class 5 Science Solutions Term 1 Chapter 2 Matter and Materials

Evaluation

I. Choose the Correct Answer:

Question 1. Which of the following are the states of matter?
(a) Solid, Liquid, Water
(b) Solid, Liquid, Gas
(c) Solid, Liquid, Wood
(d) Solid, Liquid, Sugar
Answer: (b) Solid, Liquid, Gas
In simple words: Matter can exist in three main forms: solid, liquid, and gas. These are the basic ways substances are found.

🎯 Exam Tip: Remember the three common states of matter are solid, liquid, and gas, which are defined by how their particles are arranged.

Question 2. Which of the following is a solid?
(a) Kerosene
(b) Air
(c) Water
(d) Apple
Answer: (d) Apple
In simple words: An apple keeps its own shape and size, so it is a solid. Kerosene, air, and water are not solids.

🎯 Exam Tip: Solids have a fixed shape and volume, unlike liquids or gases, which take the shape of their container.

Question 3. Jute fibre is obtained from
(a) leaf
(b) stem
(c) flower
(d) root
Answer: (b) Stem
In simple words: Jute, which is used to make strong ropes and bags, comes from the stem part of the jute plant.

🎯 Exam Tip: Many plant fibres like jute are extracted from specific parts of the plant, such as the stem, to be used for textiles or other products.

II. Fill in the blanks:

Question 1. _________ soil is suitable for growing cotton.
Answer: Black soil and alluvial soil
In simple words: Cotton plants grow best in black soil and alluvial soil because these soils have the right nutrients and water retention.

🎯 Exam Tip: Knowing which crops grow best in specific soil types is important in agriculture and for understanding local economies.

Question 2. The process of making cotton yarn from cotton fibre is _________.
Answer: Spinning
In simple words: To turn cotton fibres into yarn (thread), you use a process called spinning, which twists the fibres together.

🎯 Exam Tip: Spinning is a key step in fabric production, where raw fibres are twisted into long, continuous threads for weaving or knitting.

Question 3. Ginning is done to separate _________ from the seeds.
Answer: Raw fibres
In simple words: Ginning is the process where machines pull the raw cotton fibres away from the cotton seeds.

🎯 Exam Tip: Ginning is an essential first step after harvesting cotton to prepare the fibres for further processing into textiles.

Question 4. Synthetic fibre is also called _________.
Answer: Artificial fibre
In simple words: Fibres made by people in factories are called synthetic or artificial fibres, because they are not found in nature.

🎯 Exam Tip: Synthetic fibres are man-made and often designed for specific properties like strength, elasticity, or water resistance.

Question 5. Woolen clothes are manufactured from _________.
Answer: Plant / animals
In simple words: Woolen clothes come from animal fibres, mainly from sheep. People use these fibres to make warm clothing.

🎯 Exam Tip: Wool is a natural animal fibre known for its warmth and softness, commonly used in winter clothing and blankets.

III. Match the following:

Question 1.
1. Yarn
2. Lint
3. Fabrics
4. Rayon
5. Jute
a) Ginning
b) Spinning
c) Wood pulp
d) Stem
e) Weaving
Answer:
1. b
2. a
3. e
4. c
5. d
In simple words: This match shows how different parts of fibre making and materials connect. Yarn is made by spinning, lint is separated by ginning, fabrics are made by weaving, rayon comes from wood pulp, and jute is from the stem.

🎯 Exam Tip: When matching, look for direct cause-and-effect relationships or source-to-product links between the items.

IV. Say True or False:

Question 1. Coir is the outer covering of coconut.
Answer: True
In simple words: Coir is the rough, hairy fibre found on the outside of a coconut, which is used for making mats and ropes.

🎯 Exam Tip: Remember that coir is a natural fibre specifically sourced from the husk of coconuts, often used in gardening and upholstery.

Question 2. Beans and peas are pulses.
Answer: False
In simple words: Beans and peas are actually legumes, not pulses. Pulses are the dried edible seeds of legume plants.

🎯 Exam Tip: While often grouped, pulses are a specific type of legume (the dried edible seeds), differentiating them from fresh beans or peas.

Question 3. Table is a household good.
Answer: True
In simple words: A table is something commonly found and used inside a home, making it a household good.

🎯 Exam Tip: Household goods include all items typically used for daily living or furnishing a home.

Question 4. Sweet corn is not a product of maize.
Answer: False
In simple words: Sweet corn is indeed a type of maize (corn), grown for its sugary kernels. It is a direct product of the maize plant.

🎯 Exam Tip: Maize is another name for corn, and sweet corn is a popular variety harvested while still young and tender.

Question 5. Cotton balls contain jute fibre.
Answer: False
In simple words: Cotton balls contain only cotton fibres. Jute fibre comes from a different plant and is never mixed with cotton balls.

🎯 Exam Tip: Distinguish between different natural fibres and their sources; cotton comes from the cotton plant, and jute from the jute plant.

V. Complete the Given Analogy:

Question 1. Solid: Table:: Gas: _________.
Answer: Compressible
In simple words: Just as solids like a table cannot be easily squeezed, gases can be squeezed easily, meaning they are compressible.

🎯 Exam Tip: Analogies often test your understanding of key properties; solids are incompressible, while gases are highly compressible.

Question 2. Hemp: Animal fibre:: _________: Wool.
Answer: Plant fibre
In simple words: If hemp is a plant fibre, then wool is an animal fibre, both being natural types of material.

🎯 Exam Tip: Remember the basic classification of natural fibres into plant-based (like hemp, cotton, jute) and animal-based (like wool, silk).

Question 3. Maize product: Tortilla chips:: Wheat products: _________.
Answer: Pasta
In simple words: Just as tortilla chips are made from maize, pasta is a common food product made from wheat.

🎯 Exam Tip: This analogy tests your knowledge of common food sources and the products derived from them.

Question 4. _________: Films:: Nylon: Fishing nets.
Answer: Polyester
In simple words: Nylon is used for fishing nets because it is strong. Similarly, polyester is used to make films, showing a material-to-product link.

🎯 Exam Tip: When dealing with synthetic materials, think about their specific properties that make them suitable for particular uses.

VI. Answer Brief:

Question 1. What is known as ginning?
Answer: Ginning is the process of separating the raw cotton fibres from their seeds. This step is very important after cotton is harvested. The machine used for this is called a cotton gin.
In simple words: Ginning is when you take the raw cotton and remove the seeds from it.

🎯 Exam Tip: Clearly define ginning as the process of seed separation from cotton fibres, mentioning its importance in textile production.

Question 2. Give two examples of food products made from wheat.
Answer: Two examples of food products made from wheat are breads and cakes. Other products include pasta, wheat germ, and cracked wheat. Wheat is a versatile grain used in many common foods.
In simple words: Breads and cakes are two foods made from wheat.

🎯 Exam Tip: When asked for examples, choose common and distinct items that clearly represent the category.

Question 3. What are synthetic fibres?
Answer: Synthetic fibres are man-made fibres created by humans using chemical processes. They are also called artificial fibres. These fibres are often made from materials like coal, petroleum, and natural gas. Rayon, nylon, polyester, and acrylic are common examples.
In simple words: Synthetic fibres are artificial threads made by people in factories using chemicals, not found in nature.

🎯 Exam Tip: Remember that synthetic fibres are distinct from natural fibres because they are manufactured through chemical processes, giving them specific engineered properties.

Question 4. What is known as upthrust?
Answer: Upthrust is the upward force that a liquid exerts on an object when it is put into the liquid. This force makes objects feel lighter or even float. If an object's weight is more than the upthrust, it sinks; if it's less, it floats, like an empty water bottle.
In simple words: Upthrust is the push-up force a liquid gives to an object placed in it.

🎯 Exam Tip: When defining upthrust, clearly state that it is an upward force from a fluid and explain how it relates to an object's ability to float or sink.

Question 5. Name the list of whole grains.
Answer: Some common examples of whole grains include wheat, maize, rice, beans, peas, barley, and millets. These grains contain all parts of the kernel, making them more nutritious.
In simple words: Wheat, maize, rice, beans, peas, barley, and millets are all whole grains.

🎯 Exam Tip: Whole grains retain their bran, germ, and endosperm, providing more fibre and nutrients compared to refined grains.

VII. Answer in Detail:

Question 1. Discuss briefly about three states of matter.
Answer: Matter is anything that has mass and takes up space. It commonly exists in three main states: solid, liquid, and gas. Understanding these states helps explain how different substances behave.
a) **Solid:** In solids, molecules are packed very closely together. Solids cannot be easily compressed. They have a definite shape, size, and volume. For example, a table, a book, or metals keep their shape.
b) **Liquid:** In liquids, molecules are loosely packed. Liquids are not easily compressed. They have a definite volume but no fixed shape; they take the shape of their container. Examples include water, milk, and petrol.
c) **Gas:** In gases, molecules are very far apart and move freely. Gases can be highly compressed. They have no definite shape or volume, and will fill any container they are in. Examples are air, LPG, and oxygen.
In simple words: Matter comes in three forms: solids, which are firm and keep their shape; liquids, which flow and take the container's shape; and gases, which spread out and fill all available space.

🎯 Exam Tip: When describing states of matter, focus on the arrangement of molecules and the properties of shape, volume, and compressibility for each state.

Question 2. Draw a flow chart to indicate the process of making fabrics from cotton ball.
Answer: The process of making fabrics from cotton balls involves several key steps. Each step transforms the cotton into a more refined material.
1. **Cotton balls:** Raw cotton is collected from the plants.
2. **Ginning:** The cotton balls are processed to separate the cotton fibres from the seeds.
3. **Cotton fibre:** The separated fibres are now ready for the next stage.
4. **Lint:** The cleaned cotton fibre, called lint, is prepared for spinning.
5. **Spinning:** The lint is twisted to create cotton yarn.
6. **Yarn:** The yarn is now ready for weaving or knitting.
7. **Weaving / Knitting:** Yarn is interlaced (weaving) or looped (knitting) to form fabric.
8. **Fabric:** The final product is a usable cloth or textile.
In simple words: First, you get cotton balls, then remove seeds (ginning) to get fibres (lint). These fibres are spun into yarn, and then the yarn is woven or knitted to make fabric.

🎯 Exam Tip: When describing a process, list each step clearly in sequence and briefly explain what happens at each stage.

VIII. Give Reason:

Question 1. Why umbrellas are made up of synthetic clothes?
Answer: Umbrellas are made from synthetic clothes because these fibres are more water-resistant (hydrophobic) than natural fibres like cotton or wool. Synthetic fabrics, such as nylon and polyester, are commonly used because they do not absorb water easily, helping umbrellas keep you dry. This property prevents water from soaking through and makes the umbrella dry faster.
In simple words: Umbrellas are made from man-made (synthetic) cloth like nylon or polyester because these materials do not soak up water easily, keeping rain out.

🎯 Exam Tip: Focus on the property of hydrophobicity (water resistance) when explaining why synthetic fibres are preferred for umbrellas.

Question 2. What determines whether an object floats or sinks in a fluid?
Answer: Whether an object floats or sinks in a fluid is determined by its density compared to the fluid's density, and the upward force exerted by the fluid, called upthrust. If an object is placed in a liquid, the liquid pushes up on it with a force (upthrust). If the object's weight is more than this upthrust, it sinks. But if its weight is less than the upthrust (like an empty water bottle), it floats. An object floats if it is less dense than the fluid it is in, and sinks if it is denser.
In simple words: An object floats or sinks based on its density and the upward push (upthrust) from the fluid. Lighter-than-water objects float, heavier ones sink.

🎯 Exam Tip: Explain both density and upthrust in your answer, as they are interconnected concepts that explain flotation and sinking.

Book Activities:

Activity 1. Look at your surroundings. Give some examples of solid, liquid, and gases.
Answer: Here are some examples of solids, liquids, and gases you can find around you:

🎯 Exam Tip: When giving examples, try to pick common items that clearly fit into each category of matter to show a strong understanding.

Activity 2. Classify the following Natural Fibres: Polyster, Jute, Silk, Nylon, Cotton, Wool, Acrylic, Rayon.
Answer: Fibres can be grouped into natural and synthetic types. Natural fibres come from plants or animals, while synthetic ones are man-made.

🎯 Exam Tip: Clearly distinguish between natural (from plants/animals) and synthetic (man-made) fibres when classifying them.

Activity 3. Take water in a bucket and drop the following items in the water. Apple, Scissors, Silver fork, Marbles, Plastic ball. Fill the table with your observation.
Answer: When different items are dropped into water, some float and some sink, depending on their density.

🎯 Exam Tip: Remember that an object floats if it is less dense than the liquid, and sinks if it is more dense.

Activity 4. Collect some samples of solid substances such as salt, sugar, chalk powder, sand and saw dust. Take five beakers filled with water and add a small amount of sugar to the first beaker, salt to the second and similarly, add small amounts of other substances in other beakers. Stir the content with a glass rod. Wait for few minutes. What happens to the substances added? Note your observation.
Answer: When different solids are added to water, some will dissolve completely, while others will not. This shows the property of solubility.

🎯 Exam Tip: Distinguish between soluble substances (like salt and sugar) that dissolve to form a uniform mixture, and insoluble substances (like sand) that do not.

Activity 5. Collect samples of coconut oil, kerosene, mustard oil, lemon juice, and vinegar. Take five test tubes, fill them up to half with water. Add a spoon full of one liquid to this and stir it well. Keep it in a test tube stand and wait for few minutes. Observe whether the liquid mixes with water. Repeat the experiment with other liquids and tabulate your observation.
Answer: Some liquids mix with water (miscible), while others do not (immiscible). This experiment shows how different liquids behave when combined with water.

🎯 Exam Tip: Liquids that mix evenly with each other are called miscible, while those that do not mix and form separate layers are called immiscible.

I. Choose the Correct Answer:

Question 1. Which of these is a synthetic fibre.
(a) Cotton
(b) Jute
(c) Rayon
(d) Hemp
Answer: (c) Rayon
In simple words: Rayon is a man-made fibre, while cotton, jute, and hemp are natural fibres that come from plants.

🎯 Exam Tip: Remember that synthetic fibres are manufactured, distinguishing them from natural fibres which come from plants or animals.

Question 2. The natural fibre obtained from animal is _________.
(a) Rayon
(b) Nylon
(c) Silk
(d) Jute
Answer: (c) Silk
In simple words: Silk comes from silkworms, making it a natural fibre from an animal. Rayon, nylon, and jute are not animal fibres.

🎯 Exam Tip: Identify animal fibres by their origin, such as silk from silkworms or wool from sheep, as opposed to plant or synthetic sources.

Question 3. _________ is used for making dhotis and sarees.
(a) Cotton
(b) Jute
(c) Coir
(d) All of the options
Answer: (a) Cotton
In simple words: Cotton is a common and soft fabric used widely to make traditional Indian clothes like dhotis and sarees.

🎯 Exam Tip: Consider the common properties of fabrics like softness, breathability, and drape when determining their suitability for specific garments.

Question 4. A cotton plant is a bushy plant of _________ feet hight.
(a) 4-5
(b) 5-6
(c) 6-7
(d) 7-8
Answer: (b) 5-6
In simple words: Cotton plants usually grow to be about 5 to 6 feet tall, forming a bushy shape.

🎯 Exam Tip: Specific numerical facts like plant height are best memorized directly for accuracy.

Question 5. Which state of matter has a definite shape.
(a) liquid
(b) solid
(c) gas
(d) all the above
Answer: (b) solid
In simple words: Solids are the only state of matter that keeps its own definite shape, unlike liquids or gases that take the shape of their container.

🎯 Exam Tip: Remember the fundamental property of solids: they maintain a fixed shape and volume due to closely packed particles.

II. Fill in the blanks:

Question 1. _________ is an important process for making fabric from the yarn.
Answer: knitting
In simple words: Knitting is a major way to make fabric from yarn by looping the thread together.

🎯 Exam Tip: Knitting and weaving are two primary methods of fabric construction from yarn, each producing different textures and properties.

Question 2. Impurities of the cotton fibre can be removed by the process _________.
Answer: combing
In simple words: Combing is a process used to clean cotton fibres and take out any small pieces of dirt or shorter fibres.

🎯 Exam Tip: Combing is a refining step in cotton processing that ensures only long, clean fibres are used for high-quality yarn.

Question 3. The world's most valuable fibre is _________.
Answer: Vicuna
In simple words: Vicuna wool is known as the most expensive fibre because it is very rare and incredibly soft.

🎯 Exam Tip: Rare natural fibres often command high value due to their unique properties and limited availability.

Question 4. _________ is used as a sweetener instead of sugar.
Answer: Corn syrup
In simple words: Corn syrup is a thick, sweet liquid made from corn, often used as a sugar substitute in many foods.

🎯 Exam Tip: Many different types of sweeteners exist, each with a distinct source and chemical composition.

Question 5. The process of twisting the fibres into yarn is called _________.
Answer: spinning
In simple words: When you twist raw fibres together to make a long thread, that process is called spinning.

🎯 Exam Tip: Spinning is a foundational step in textile manufacturing, converting loose fibres into strong, continuous yarn.

III. Match the following:

Question 1.
1. Yarn
2. Lint
3. Maize
4. Cotton seeds
(a) Fibrous bran
(b) Sorghum
(c) Lint
(d) Corn
Answer:
1. (b) Sorghum
2. (a) Fibrous bran
3. (d) Corn
4. (c) Lint
In simple words: This question matches raw materials or products with their descriptions or categories. It tests your knowledge of different types of fibres and grains.

🎯 Exam Tip: When matching, draw lines or write numbers next to the correct pair. Double-check each match to avoid errors, especially when options are similar.

Question 2.
1. Rayon
2. Nylon
3. Polyester
(a) Silk and wool
(b) Petroleum products
(c) Wool products
Answer:
1. (b) Petroleum products
2. (b) Petroleum products
3. (b) Petroleum products
In simple words: This question asks about the sources of different synthetic fibres. Rayon, nylon, and polyester are all man-made fibres that come from petroleum products.

🎯 Exam Tip: Remember that synthetic fibres are manufactured from raw materials like petroleum, unlike natural fibres that come from plants or animals.

Question 3.
1. Flax
2. Silk
3. Acrylic
4. Coconut
(a) Animal fibre
(b) Plant fibre
(c) Coir fibre
(d) Synthetic fibre
Answer:
1. (b) Plant fibre
2. (a) Animal fibre
3. (d) Synthetic fibre
4. (c) Coir fibre
In simple words: This question matches different fibres to their main categories. Flax comes from plants, silk from animals, acrylic is man-made, and coir is a specific fibre from coconuts.

🎯 Exam Tip: Classify fibres into natural (plant/animal) and synthetic (man-made) categories. This helps in correctly identifying their origins.

IV. Say True or False:

Question 1. Solids are compressible.
Answer: False
In simple words: Solids are not easy to squeeze because their parts are packed very closely. Imagine trying to squish a rock – it won't change its size much.

🎯 Exam Tip: Remember that solids have a fixed shape and volume, making them generally incompressible compared to liquids and gases.

Question 3. The fibrous material left after separating cotton seeds is called lint.
Answer: True
In simple words: After removing cotton seeds, the soft cotton fibres that are left are known as lint. This is the part used to make thread.

🎯 Exam Tip: Understand the term 'lint' in the context of cotton processing; it refers specifically to the cleaned cotton fibres.

Question 4. Barley and maize are grains.
Answer: True
In simple words: Both barley and maize (corn) are types of grains that are grown and harvested for food. Grains are seeds from grasses.

🎯 Exam Tip: Know common examples of grains, as they are a fundamental food group. Barley and maize are good examples.

Question 5. Maize is also known as rice.
Answer: False
In simple words: Maize is commonly called corn, and it is different from rice. They are both grains but come from different plants and have different uses.

🎯 Exam Tip: Be precise with scientific and common names of crops. Maize and rice are distinct food items.

Question 6. White rice contains essential nutrients.
Answer: True
In simple words: While brown rice has more fibre, white rice still gives us important nutrients like carbohydrates and some vitamins, which are good for energy.

🎯 Exam Tip: Recognize that all food sources provide some nutrients, even if some forms are more nutrient-dense than others. White rice is primarily an energy source.

Question 7. Coir fibre is obtained from the Jute.
Answer: False
In simple words: Coir fibre comes from the outer shell of coconuts, while jute fibre comes from the stem of the jute plant. They are from entirely different sources.

🎯 Exam Tip: Distinguish between different natural fibres based on their plant or animal origin to avoid confusion.

Question 8. White rice is usually considered much healthier than Brown rice.
Answer: False
In simple words: Brown rice is generally thought to be healthier than white rice because it has more fibre and other nutrients. This is because brown rice keeps its outer layers.

🎯 Exam Tip: Understand the nutritional differences between whole grains (like brown rice) and refined grains (like white rice) due to processing.

V. Complete the Analogy:

Question 1. Solids: incompressible:: Gas: ______
Answer: Compressible
In simple words: Solids cannot be easily squeezed, but gases can be squeezed easily because their particles are far apart. This means you can fit more gas into a small space.

🎯 Exam Tip: Analogies test your understanding of relationships. Here, the relationship is the opposite characteristic for states of matter.

Question 2. Hemp: ______ :: Wool: Animal fibre
Answer: Plant fibre
In simple words: Hemp is a type of fibre that comes from a plant, just like wool is a fibre that comes from an animal. This shows how different fibres have different natural sources.

🎯 Exam Tip: Identify the source category (plant, animal, synthetic) for various fibres to complete such analogies correctly.

Question 3. Maize product: Tortilla chips:: ______ : Pasta
Answer: Wheat products
In simple words: Tortilla chips are made from maize (corn). In the same way, pasta is a food product made from wheat. These examples link a grain to a food made from it.

🎯 Exam Tip: Connect common food items to the main ingredient they are made from, such as grains and their processed forms.

Question 4. ______ : Films:: Nylon: Fishing nets.
Answer: Polyester
In simple words: Polyester is used to make films, and nylon is used to make fishing nets. Both are synthetic materials used for different products.

🎯 Exam Tip: Be aware of the common uses and applications of different synthetic fibres in everyday products.

VI. Circle the odd one:

Question 1.
(a) Ginning
(b) Spinning
(c) Filling
(d) Weaving
Answer: (c) Filling
In simple words: Ginning, spinning, and weaving are all steps in making fabric from cotton. Filling is not a step in this process.

🎯 Exam Tip: Know the sequential steps involved in fibre processing to easily identify an unrelated term.

Question 2.
(a) Sweet corn
(b) Tortilla chips
(c) Pasta
(d) Taco
Answer: (c) Pasta
In simple words: Sweet corn, tortilla chips, and tacos are all products made from maize (corn). Pasta is usually made from wheat, so it is the odd one out.

🎯 Exam Tip: Group food items by their primary ingredient to find the one that doesn't belong to the same group.

Question 3.
(a) Chalk powder
(b) Sand
(c) Sugar
(d) Sawdust
Answer: (c) Sugar
In simple words: Chalk powder, sand, and sawdust do not dissolve in water. Sugar, however, dissolves easily in water, making it the different one.

🎯 Exam Tip: Think about the solubility of each substance in water to determine which one behaves differently.

Question 4.
(a) Vinegar
(b) Mustard oil
(c) Kerosene
(d) Coconut oil
Answer: (a) Vinegar
In simple words: Mustard oil, kerosene, and coconut oil are all oils or oil-based liquids. Vinegar is an acid-based liquid, not an oil, making it the odd one out.

🎯 Exam Tip: Classify liquids based on their chemical nature (e.g., oil, acid, water-based) to find the outlier.

Question 5.
(a) Wool
(b) Nylon
(c) Rayon
(d) Acrylic
Answer: (a) Wool
In simple words: Wool is a natural fibre from animals. Nylon, rayon, and acrylic are all man-made, synthetic fibres. So, wool is the odd one.

🎯 Exam Tip: Differentiate between natural and synthetic fibres. Wool, silk, cotton, and jute are natural; nylon, rayon, and polyester are synthetic.

VII. Answer briefly:

Question 1. What is material?
Answer: A material is what an object is made of. It can be a pure substance or a mixture of different substances. Materials can be found in nature or made by humans.
In simple words: A material is the stuff an object is built from. It can be simple or mixed, and it comes from nature or is made by people.

🎯 Exam Tip: Define 'material' by mentioning its composition (pure/mixture) and origin (natural/man-made) to give a complete answer.

Question 2. What kind of soil is needed for growing cotton?
Answer: Cotton grows well in black soil and alluvial soil. These soils are rich in nutrients and can hold water, which is good for the cotton plant.
In simple words: Cotton needs black soil and alluvial soil to grow best.

🎯 Exam Tip: Remember specific soil types mentioned for particular crops, as this shows detailed knowledge.

Question 3. What are cotton balls?
Answer: Cotton balls are the small, green, fluffy pods that grow on a cotton plant. These pods contain the cotton fibres and seeds. When they ripen, they burst open, showing the white cotton.
In simple words: Cotton balls are the small, green pods on a cotton plant that hold the cotton fibre.

🎯 Exam Tip: Describe cotton balls as part of the plant's growth cycle, emphasizing their function of holding the fibres.

Question 4. What is Ginning?
Answer: Ginning is the process where raw cotton fibres are separated from their seeds. This step is important before the cotton can be spun into yarn.
In simple words: Ginning is how we take out the seeds from raw cotton fibres.

🎯 Exam Tip: Define ginning clearly by stating both what is separated (fibres) and what it's separated from (seeds).

Question 5. Mention the two uses of cotton?
Answer:
* Cotton is widely used to make textiles and garments like clothes, towels, and bedsheets.
* It is also used as a soft filling in pillows and mattresses. Cotton's softness makes it suitable for surgical bandages too.
In simple words: Cotton is used to make clothes and as a soft filling for things like pillows.

🎯 Exam Tip: Provide diverse uses of cotton, including both clothing and household items, to show a broad understanding.

Question 6. Why jute fibre is called as Golden fibre?
Answer: Jute fibre is called "Golden fibre" because of its shiny, golden-brown colour. It is also known for being affordable and widely available.
In simple words: Jute is called "Golden fibre" because of its golden colour and because it is cheap and easy to find.

🎯 Exam Tip: When explaining nicknames for materials, mention both their physical appearance and any key economic characteristics.

Question 7. Write the uses of Jute?
Answer:
* Jute is used to make bags, carpets, ropes, and curtains because it is strong.
* It is also used to make some rough clothes for packing things, like bales of raw cotton or grains, and for decorative wall hangings.
In simple words: Jute is used for making bags, carpets, ropes, and some clothing for packaging.

🎯 Exam Tip: List a variety of uses for jute, focusing on its strength and durability in products like bags and carpets.

Question 8. What are synthetic fibres?
Answer: Synthetic fibres are man-made fibres created by humans through chemical processes. They are also known as artificial fibres and are often made from materials like coal, petroleum, and natural gas.
In simple words: Synthetic fibres are artificial fibres made by people using chemicals, often from oil.

🎯 Exam Tip: Define synthetic fibres by emphasizing their man-made nature and their origin from chemical compounds like petroleum.

Question 9. Give an example of food products made from rice?
Answer: Some food products made from rice include idly, Idiappam, and flattened rice (Rice aval). Rice is a very common staple food and is used in many different dishes.
In simple words: Idly, Idiappam, and flattened rice are foods made from rice.

🎯 Exam Tip: Provide specific examples of common dishes made from rice to demonstrate practical knowledge.

Question 10. Will eating millets reduce weight?
Answer: Yes, eating millets can help with weight loss because they are rich in fibre. Fibre helps you feel full for longer, which can lead to eating less.
In simple words: Yes, eating millets can help reduce weight because they have a lot of fibre.

🎯 Exam Tip: Connect the nutritional content of millets (high fibre) to its health benefit (weight loss) for a comprehensive answer.

Question 11. What are household goods?
Answer: Household goods are items that we use in our homes. These are things that are found permanently in a house and include furniture, kitchenware, clothes, towels, beddings, and electronic goods.
In simple words: Household goods are all the items we use and keep in our house, like furniture and kitchen tools.

🎯 Exam Tip: Provide a clear definition of household goods and list several diverse examples to illustrate your understanding.

Question 12. What insoluble substance? Give examples.
Answer: Insoluble substances are those that do not dissolve in water. Examples include chalk powder, sand, and sawdust. These materials will not disappear even if stirred in water.
In simple words: Insoluble substances do not dissolve in water, like chalk powder, sand, or sawdust.

🎯 Exam Tip: Clearly define insoluble substances and give at least two distinct examples for full marks.

VIII. Answer in Detail:

Question 1. Write a note on fibres.
Answer: Fibres are thin threads that can come from natural or artificial sources. They are used to make clothes and other products with machines like power looms.
* Natural fibres are obtained from plants and animals. Cotton, jute, coir, flax, and hemp are examples of plant fibres. Wool and silk are examples of animal fibres.
* Synthetic fibres are created by humans using chemical processes. Rayon, nylon, acrylic, and dacron are examples of artificial fibres, often made from petroleum.
In simple words: Fibres are thin threads used to make clothes. They can be natural, from plants or animals, or synthetic, made by humans using chemicals.

🎯 Exam Tip: Structure your answer by clearly distinguishing between natural and synthetic fibres, providing examples for each type to show detailed knowledge.

Question 2. Write the uses of synthetic fibres.
Answer: Synthetic fibres are very versatile and are used in many different ways:
* Rayon is used to make ropes, cloth, caps, tyre cords, and carpets due to its strength and softness.
* Nylon is used for fishing nets, ropes, parachutes, fabrics, and bristles for brushes because it is strong and elastic.
* Polyester is used to make fabric for suits and shirts, hoses, conveyor belts, films, PET bottles, and wires, known for its durability and wrinkle resistance.
* Acrylic is used to make sweaters, shawls, and blankets because it is soft and warm, similar to wool.
In simple words: Synthetic fibres like rayon, nylon, polyester, and acrylic are used for many things, including clothes, ropes, bottles, and blankets, because they are strong and durable.

🎯 Exam Tip: When listing uses, group them by specific fibre type if possible, or by product category, to make the answer clear and organized.

Question 3. Explain about the solubility of solids in water with examples.
Answer: The solubility of solids in water describes whether a solid can dissolve in water or not. There are two main types:
* Soluble substances completely dissolve in water, meaning they disappear and mix uniformly to form a solution. For example, sugar and salt are soluble in water.
* Insoluble substances do not dissolve in water, even after stirring for a long time. These substances remain visible and do not mix with the water. Examples include chalk powder, sand, and sawdust.
In simple words: Some solids dissolve in water and disappear, like sugar (these are soluble). Other solids, like sand, do not dissolve in water and stay visible (these are insoluble).

🎯 Exam Tip: Define both soluble and insoluble substances clearly, and provide distinct examples for each to illustrate the concept effectively.