Samacheer Kalvi Class 4 Science Solutions Term 1 Chapter 2 Matter and Materials

I. Pick Out the Odd One:

 

Question 1. brick. coir. silk cloth. pine apple
Answer: Silk cloth
In simple words: Bricks, coir, and pine apples are natural materials, while silk cloth is a processed fabric made from silk fibers. Silk is the only one here that is not a raw natural item.

🎯 Exam Tip: When picking the odd one out, always look for a common property or category that most items share, and identify which item does not fit into that group.

 

Question 2. stone, rubber band, cycle tube, electric wire
Answer: Stone
In simple words: Rubber band, cycle tube, and electric wire are all flexible materials, meaning they can bend easily. Stone is a hard and rigid material that cannot be bent.

🎯 Exam Tip: Categorize items based on their properties like flexibility, hardness, or source to find the one that doesn't belong.

 

Question 3. sun, candle, torch, pen
Answer: Pen
In simple words: The sun, a candle, and a torch are all sources of light. A pen is used for writing and does not produce light.

🎯 Exam Tip: Pay attention to the primary function or nature of each item to correctly group them and find the outlier.

 

Question 4. umbrella, sponge, rain coat, jerkin
Answer: Sponge
In simple words: An umbrella, raincoat, and jerkin are all items designed to keep water out or protect you from rain. A sponge is designed to absorb water, making it different from the others.

🎯 Exam Tip: Think about the main purpose of each object to distinguish it from a group of similar items.

 

Question 5. glass bottle, exam pad, paper plate, wooden board
Answer: Glass bottle
In simple words: An exam pad, paper plate, and wooden board are all made from materials that absorb water. A glass bottle is made of glass, which is waterproof and does not absorb water.

🎯 Exam Tip: Consider the material and its properties (like water absorption) when deciding which item is the odd one out.

II. Fill in the Blanks:

 

Question 1. Materials which can be compressed or cut easily are called __________
Answer: Soft
In simple words: Materials that are easy to squeeze or cut are called soft materials. You can easily change their shape.

🎯 Exam Tip: Remember that softness is about how easily a material can change its shape under pressure.

 

Question 2. Gold and diamond are the examples of _________ materials.
Answer: Shiny
In simple words: Gold and diamond are known for their bright, reflective surfaces. Materials that reflect light well and look bright are called shiny materials.

🎯 Exam Tip: Think about how light interacts with the surface of the material to determine if it is shiny or dull.

 

Question 3. Materials which can be bent or stretched easily are called __________.
Answer: Flexible
In simple words: Flexible materials can be bent or stretched without breaking. This allows them to change shape easily, unlike rigid materials.

🎯 Exam Tip: Flexibility describes a material's ability to bend or stretch without damage, a key property for many everyday objects.

 

Question 4. _________ objects allow all the light to pass through them.
Answer: Transparent
In simple words: Transparent objects are clear and let all light pass through. This is why you can see clearly through them, like a window.

🎯 Exam Tip: An object is transparent if you can see perfectly clearly through it, as if nothing is there.

 

Question 5. _________ is the natural source that stimulates sight and makes things.
Answer: Light
In simple words: Light is what helps us see everything around us. It comes from natural sources like the sun and allows our eyes to perceive objects.

🎯 Exam Tip: Remember that light is crucial for vision and comes from both natural and artificial sources.

III. Match the Following: (Text Book Page No. 101)

 

Question 1. Match the following.
Answer:
1. Light source - Sun
2. Waterproof - Rain coat
3. Transparent - Glass
4. Translucent - Vegetable oil
5. Opaque - Metal
In simple words: We connect each item on the left with its correct description or example on the right. For instance, the Sun gives light, so it is a light source, and glass allows light to pass through completely, making it transparent.

🎯 Exam Tip: Read both columns carefully and link items based on their definition, properties, or common examples you have learned.

IV. Say True or False:

 

Question 1. We cannot compress, cut or bend the rough materials easily.
Answer: False
In simple words: The statement is false because the ability to compress, cut, or bend materials depends on their hardness or flexibility, not just if they are rough or smooth. For example, a rough sponge can be easily compressed.

🎯 Exam Tip: Distinguish between material properties like roughness (surface texture) and hardness or flexibility (how easily it deforms) to avoid common misconceptions.

 

Question 2. Dull materials reflect light.
Answer: False
In simple words: Dull materials do not reflect light well; they absorb most of it, which is why they look non-shiny. Shiny materials are the ones that reflect light strongly.

🎯 Exam Tip: Remember that shiny objects reflect light brightly, while dull objects absorb more light and reflect less, making them appear muted.

 

Question 3. Sand paper is a good example for smooth materials.
Answer: False
In simple words: Sandpaper is specially made to be rough. It has tiny sharp grains that make its surface uneven, which is useful for smoothing other objects.

🎯 Exam Tip: Always relate materials to their real-world uses; sandpaper's purpose relies on its rough texture.

 

Question 4. Opaque objects do not allow light to pass through them.
Answer: True
In simple words: Opaque objects completely block light, so you cannot see through them at all. Things like a wooden door or a brick wall are opaque.

🎯 Exam Tip: Understand that opaque materials block light entirely, unlike transparent (all light) or translucent (some light) materials.

 

Question 5. Mirrors change the direction of light that fall on them.
Answer: True
In simple words: Mirrors reflect light. When light hits a mirror, it bounces off and changes direction, which is how we see our reflection.

🎯 Exam Tip: Mirrors are excellent examples of reflective surfaces that cause light to change direction, a phenomenon known as reflection.

V. Answer the Following Questions:

 

Question 1. When can you say a material is waterproof material?
Answer: A material is called waterproof when it does not allow water to pass through it. This property makes them useful for protecting things from getting wet. For example, a raincoat or aluminum foil of a tablet strip are waterproof materials.
In simple words: A material is waterproof if water cannot get through it. Raincoats are a good example.

🎯 Exam Tip: Always mention both the definition and an example when asked to describe a material property like waterproof.

 

Question 2. What is a light source?
Answer: Objects that produce and give off light on their own are called light sources. These sources can be natural, like the sun, or artificial, such as an electric lamp or a light bulb.
In simple words: A light source is anything that makes light, like the sun or a bulb.

🎯 Exam Tip: When defining "light source", ensure you include examples of both natural and artificial sources.

 

Question 3. What is the difference between transparent and opaque materials?
Answer:

Transparent materials let all light pass through, making them clear, while opaque materials block all light. This difference in light interaction makes them suitable for various uses, such as clear windows versus solid walls.
In simple words: Transparent things let you see through them because all light passes. Opaque things block all light, so you cannot see through them.

🎯 Exam Tip: When differentiating, always provide a clear definition for each type, explain the key difference (light passage), and give relevant examples.

 

Question 4. Define reflection.
Answer: Reflection is the process where light bounces off a smooth or polished surface. This phenomenon allows us to see images in mirrors and shiny objects.
In simple words: Reflection is when light hits a smooth surface and bounces back.

🎯 Exam Tip: Remember that reflection requires a smooth or polished surface for light to bounce off in a clear way.

 

Question 5. Classify the objects given below as transparent, translucent or opaque materials.
(Air, Rock, Water, Aluminium foil, Mirror, Snow, Wooden board, Polythene bag, CD, Oil soaked paper, Glass tumbler and Coloured glass)
Answer:

Understanding how much light each material lets through helps us classify them correctly. For instance, clear air is transparent, while a colored glass allows some light but blurs the view, making it translucent.
In simple words: Transparent means light passes through clearly, translucent means some light passes but looks blurry, and opaque means no light passes through at all.

🎯 Exam Tip: To classify correctly, visualize each object and consider how much light would pass through it and how clear the view would be on the other side.

Samacheer Kalvi 4th Science Guide Matter and Materials Intext Questions and Answers

Try to Answer: (Text Book Page No. 95)

 

Question 1. Look at the pictures and identify the materials by which they are made of : (paper, clay, glass, wood, plastic, metal rubber, wax)
Answer:

By looking at the visual characteristics of each item, like its texture, shape, and common uses, we can determine the material it is made from. For example, the pipes are clearly plastic, while the train toy has the grain of wood.
In simple words: We can tell what things are made of by looking at how they look and feel, and what they are used for.

🎯 Exam Tip: Practice identifying common materials by their appearance and typical forms (e.g., plastic for pipes, wood for furniture).

Try to Answer: (Text Book Page No. 96)

 

Question 1. Match the objects that are made of same material
Answer:

We match items by finding out what material they are made from. For example, all plastic objects can be grouped together, all wooden objects together, and all leather objects together, even if they look very different.
In simple words: Group objects that are made from the same stuff. Like, put all plastic things together, all wood things together, and all leather things together.

🎯 Exam Tip: To match objects by material, first identify the primary material of each item, then group those that share the same material.

 

Question 1. Write whether the given materials are hard or soft.
Wood, Eraser, Cotton
Answer:

Hard materials resist changes in shape, while soft materials are easily compressed or shaped. Wood is hard, but an eraser and cotton can be squeezed and easily change shape.
In simple words: Wood is hard because you can't easily change its shape. Eraser and cotton are soft because you can squeeze them easily.

🎯 Exam Tip: Test for hardness or softness by considering if a material can be easily bent, compressed, or scratched.

Try to Answer: (Text Book Page No. 97)

 

Question 1. Sort the given objects as rough or smooth.
Wet soap, Coir, Feather, Stone, Glass ball, Paperboard, Sand paper, Plastic spoon
Answer:

Smooth objects have an even surface that feels gentle to touch, while rough objects have an uneven, bumpy, or coarse surface. For example, a glass ball is smooth, but sandpaper is very rough.
In simple words: Smooth things feel even and soft. Rough things feel bumpy and uneven.

🎯 Exam Tip: To classify objects as rough or smooth, imagine touching them and consider how flat or bumpy their surface feels.

Test the Flexibility.

 

Question 1. Give one plastic scale and wooden scale to the students. Ask them to bend. Tabulate their observation (bends, does not bend).
Answer:

Plastic is a flexible material, meaning it can change shape without breaking, while wood is rigid and will break if bent too much. This experiment clearly shows the difference in their flexibility.
In simple words: A plastic scale can bend easily, but a wooden scale is stiff and will not bend without breaking.

🎯 Exam Tip: Flexibility is a key property that determines if a material can be easily reshaped or if it will break under pressure.

Try to Answer: (Text Book Page No. 99)

 

Question 1. Write whether the objects are transparent, translucent or opaque.
Answer:

The amount of light that passes through an object determines if it is transparent, translucent, or opaque. For example, you can see clearly through a fish tank (transparent), but a red bottle blocks all light (opaque), and a foggy window lets some light through but blurs the view (translucent).
In simple words: Things you can see through clearly are transparent. Things that let some light through but look blurry are translucent. Things that block all light are opaque.

🎯 Exam Tip: To classify objects, ask yourself: Can I see through it clearly (transparent)? Can I see light but not clearly (translucent)? Or can I not see any light through it (opaque)?

Samacheer Kalvi 4th Science Guide Matter and Materials Additional Questions and Answers

I. Pick Out the Odd One:

 

Question 1. Rope, Salt paper, Mirror Ball, Wood
Answer: Mirror Ball
In simple words: A mirror ball is designed to reflect light brightly. Rope, salt paper, and wood are generally dull materials that do not reflect much light.

🎯 Exam Tip: Consider the primary surface property (shiny vs. dull) when looking for the odd one out among these materials.

 

Question 2. glass, raincoat, aluminum foil, tablet strip
Answer: Glass
In simple words: Glass is transparent, meaning you can see through it. A raincoat, aluminum foil, and a tablet strip are all waterproof or opaque materials, designed to block water or light.

🎯 Exam Tip: Focus on light transmission and waterproof properties to differentiate these items.

 

Question 3. candle, mirror, silk cloth, tiles
Answer: Candle
In simple words: A candle is a light source because it produces its own light. A mirror, silk cloth, and tiles are materials that reflect light or simply exist as surfaces, but they don't make light.

🎯 Exam Tip: Distinguish between objects that produce light and those that merely interact with existing light through reflection or absorption.

 

Question 4. stainless steel, foam, gold, diamond
Answer: Foam
In simple words: Foam is a soft material that can be easily squashed. Stainless steel, gold, and diamond are all very hard materials.

🎯 Exam Tip: Use the property of hardness or softness as the key criterion when selecting the odd item from this list.

II. Say True or False:

 

Question 1. A block of wood is opaque.
Answer: True
In simple words: Wood does not let light pass through it, so it is an opaque material. You cannot see through a block of wood.

🎯 Exam Tip: Remember that opaque materials completely block light and do not allow vision through them.

 

Question 2. A clear window is opaque.
Answer: False
In simple words: A clear window is transparent, meaning light passes through easily, and you can see clearly through it. Opaque means light is blocked.

🎯 Exam Tip: Transparent objects, like clear windows, are the opposite of opaque objects because they let light pass through.

 

Question 3. Soft materials can be early compressed.
Answer: True
In simple words: Soft materials, like sponges or cotton, can be easily squashed or pressed into a smaller space. This is a key feature of soft materials.

🎯 Exam Tip: The ability to be compressed easily is a defining characteristic of soft materials.

 

Question 4. Smooth materials do not have ups and downs
Answer: True
In simple words: A smooth material has a flat and even surface without any bumps or rough parts. This is why it feels sleek to touch.

🎯 Exam Tip: The absence of bumps or unevenness is what makes a surface feel smooth.

III. Match the Following:

 

Question 1. Match the following.
Vegetable oil - (a) Transparent
Glass - (b) Translucent
Wood - (c) Waterproof
Aluminium foil - (d) Opaque
Answer:

We match each material with its correct property based on how it interacts with light or water. Glass lets all light through, making it transparent, while wood blocks light entirely, so it is opaque.
In simple words: Connect each material to its correct quality. For example, glass is clear (transparent), and wood blocks light (opaque).

🎯 Exam Tip: Understand the definitions of transparent, translucent, opaque, and waterproof to correctly match materials to their properties.

IV. Choose the Correct Answer:

 

Question 1. Soft material
(a) Rope
(b) Soap
(c) Salt paper
(d) Stone
Answer: (b) Soap
In simple words: Soap is a soft material that can be easily molded or squeezed, unlike rope, salt paper, or stone which are much harder.

🎯 Exam Tip: When identifying a soft material, think of items that are easy to press, reshape, or deform without breaking.

 

Question 2. Which material is transparent?
(a) Glass
(b) White plastic
(c) Coir
(d) Snow
Answer: (a) Glass
In simple words: Glass allows light to pass through clearly, so you can see through it without any blur. This makes it a transparent material.

🎯 Exam Tip: Remember that transparent materials offer a clear view through them because light passes directly.

 

Question 3. An object that blocks all of the light from passing through is
(a) Transparent
(b) Clear
(c) Opaque
(d) Translucent
Answer: (c) Opaque
In simple words: An opaque object completely stops light from passing through, so you cannot see anything on the other side. This is its defining characteristic.

🎯 Exam Tip: Opaque is the term for materials that block all light; transparent means all light passes, and translucent means some light passes but is scattered.

 

Question 4. Which among the following is an example of dull material?
(a) Stainless steel
(b) Gold
(c) Candle
(d) Diamond
Answer: (c) Candle
In simple words: A dull material does not reflect light well and looks plain, unlike shiny metals. A candle has a matte or waxy surface that doesn't shine much.

🎯 Exam Tip: Remember that "dull" materials absorb more light than they reflect, making them appear non-shiny.

 

Question 5. Materials which have ups and downs on their surface are called ______.
(a) Smooth material
(b) Rough material
(c) Shiny material
(d) Hard material
Answer: (b) Rough material
In simple words: A rough material feels uneven and bumpy because its surface has many small rises and dips. This is why it doesn't feel smooth when you touch it.

🎯 Exam Tip: The texture of a material (how it feels to touch) helps classify it as either smooth or rough.

 

Question 6. Rubber band is an example of
(a) Rough material
(b) Flexible material
(c) Rigid material
(d) Smooth material
Answer: (b) Flexible material
In simple words: A rubber band can be easily bent and stretched without breaking because it is made of a flexible material. This ability to change shape and return makes it useful for many things.

🎯 Exam Tip: Flexible materials can change their shape when a force is applied and then return to their original shape once the force is removed.

V. Fill in the blanks :

 

Question 1. ______ through which light can pass partially.
Answer: Translucent
In simple words: Translucent materials let some light pass through but scatter it, so you can't see clearly through them. Think of frosted glass.

🎯 Exam Tip: Remember the three types of materials based on light passage: transparent (clear view), translucent (blurred view), and opaque (no view).

 

Question 2. ______ through which light can pass completely.
Answer: Transparent
In simple words: Transparent materials allow all light to go through them, so you can see objects on the other side very clearly. A window glass is a good example.

🎯 Exam Tip: Materials like clear glass or air are transparent because light passes through them without scattering.

 

Question 3. ______ through which light cannot pass.
Answer: Opaque
In simple words: Opaque materials block all light from passing through them, so you cannot see anything on the other side. A wooden door is opaque.

🎯 Exam Tip: Opaque objects cast clear shadows because they completely block light.

 

Question 4. Materials which reflect the light well are called _______.
Answer: Shiny material
In simple words: Shiny materials have smooth surfaces that bounce light back easily, making them look bright and reflective. Metals like silver are very shiny.

🎯 Exam Tip: The smoother a surface is, the better it will reflect light and appear shiny.

VI. Answer the following questions in one or two sentences :

 

Question 1. Name some examples for shiny materials?
Answer: Materials that reflect light very well are called shiny materials. Examples include steel, gold, and diamonds, which all have smooth surfaces that bounce light.
In simple words: Steel, gold, and diamonds are good examples of shiny materials because they reflect light brightly.

🎯 Exam Tip: When asked for examples, try to give a variety if possible, demonstrating a broad understanding.

 

Question 2. What is material?
Answer: A material is the substance from which any object is made. For example, a chair can be made of wood, an eraser from rubber, and a candle from wax. It's the basic building block of things around us.
In simple words: A material is what something is made of, like wood, rubber, or plastic.

🎯 Exam Tip: Always include simple examples when defining a basic concept like "material" to make your answer clearer.

 

Question 3. Differentiate hard and soft materials.
Answer:

Hard materials are strong and resist changes to their shape, while soft materials are easy to change or dent. This difference helps us choose the right material for different uses.
In simple words: Hard materials are tough and don't change shape easily, like a rock. Soft materials are easy to press, cut, or bend, like cotton.

🎯 Exam Tip: When differentiating, always use clear comparative points and provide specific examples for each category.

 

Question 4. What happens when light hits a transparent object?
Answer:

• Transparent objects allow the light to pass through them.
• So, we can see other objects clearly through transparent objects.
• Examples: Air, glass, and pure water. Transparent materials are essential for clear visibility, like windows.

In simple words: When light hits a transparent object, it goes straight through, allowing us to see clearly to the other side.

🎯 Exam Tip: Clearly state that light passes through and that objects can be seen clearly, along with relevant examples.

 

Question 5. What happens when light hits a translucent object?
Answer:

• Translucent objects allow some light to pass through them.
• However, we cannot see objects clearly through them; instead, we see blurred images. This is because the light is scattered as it passes through.
• Examples: Paper soaked in oil, snow, and vegetable oil.

In simple words: When light hits a translucent object, some light gets through but is scattered, so things look blurry on the other side.

🎯 Exam Tip: For translucent objects, highlight the "partial light passage" and "blurred vision" as key characteristics.

 

Question 6. What is light sources?
Answer:

• Light may come either from the Sun or from other sources like an electric lamp or a bulb.
• The objects that give off light on their own are called light sources. The sun is a natural light source, while lamps are artificial.

In simple words: Light sources are things that make their own light, like the sun, a lamp, or a bulb.

🎯 Exam Tip: Distinguish between natural light sources (like the sun) and artificial light sources (like lamps) when explaining.