NIOS Class 10 Matter in Our Surroundings Worksheet 2 Solutions

In this post you will find answers of questions of Worksheet -2 NIOS class 10 science (Code-212) Chapter 2- Matter in Our Surroundings with complete explanation. You can also go through the workseet-3 solutions.

 

Q1. Observe your daily routine and make a list of things you smell, eat, drink and use throughout the day. Observe is there any similarity in material used throughout the day?

Answer

We interact with various substances and things with our senses throughout the day.

Things I smell	Things I eat	Things I drink	Things I use
Soap/shampoo	Roti	Water	Toothpaste
Perfume	Rice	Milk	Brush
Cooked food	Vegetables	Tea	Pen
Incense stick	Fruits	Juice	Notebook
Flowers	Biscuits	Cold drinks	Clothes

Most of the things I smell, eat, drink or use are made up to matter and found in three physical states – solid, liquid and gas.

These things can be classified into following:

(i)     Solids – Toothbrush, soap, pen, notebook, biscuits, fruits

(ii)   Liquids –water, tea, milk, juice, cold drinks

(iii)   Gases – Fragrance of perfumes, smell of cooked food, smoke of incense sticks.

 

Q2. A solid is defined as” a matter with definite size and shape which do not change on their own”. Take a rubber band and stretch it, you will observe that it changes its shape on stretching? Is it a solid? Support your answer with suitable reason.

Answer 

Yes, rubber band is a solid. When it is stretched, it changes its shape but returns to its original shape when the force is removed. This is due to elastic property of rubber band.

A solid is a substance that has a definite shape and volume and the rubber band has a definite shape under normal conditions unless an external force is applied.

Therefore, rubber band is a solid because:

   1. It has definite shape and volume when not stretched.

   2. It has property of elasticity.

 

Q3. Take different matters form your surroundings and classify the matter in different ways and make a table below

Name of matter	Solid	Liquid	Gas
Book	Solid

 

Comment why different matter has different states of matter?

Answer

Name of Matter	Solid	Liquid	Gas
Book
Water
Chair
Smoke
Milk
Mobile

 

We can see different matters in the table above. These matters exist in different physical states – solid, liquid and gas due to difference in arrangement of particles and the force of attraction between them.

(i)     Solids have tightly packed particles with strong force of attraction, so they have fixed shape and volume.

(ii)    Liquids have loosely packed particles and weaker force of attraction, so they have no fixed shape but fixed volume.

(iii)   Gases have large space between particles and they are continuously moving. There is very weak force of attraction these particles so gases have neither fixed shape nor fixed volume.

So, the states of matter depend on particles arrangement and attraction force.

 

 

Q4. Take water in liquid state and heat the water gradually till temperature 100C. secondly cool the water till temperature 0C. write your observations. Plot the temperature verses time graph of water. (Do the experiment in the presence of guardian).

 

Answer

Observation

(1)      On heating

When we heat water, the temperature of water increases gradually. At 100ºC water starts boiling and converts into steam.

The temperature remains constant (100ºC) during boiling even though heating continues. The heat is used for the change of state (liquid to gas) is called latent heat of vaporisation.

(2)      On cooling

When steam is cooled down, the temperature decreases gradually. Water begins to freeze at 0ºC. the temperature remains constant (0ºC)

The heat is released during the change of state () is known as latent heat of fusion.

 

Q5. Continue to the Q4 – explain why the temperature of water remains constant during its boiling point?

 

Answer

The temperature of water remains constant at 100ºC during it boiling. The heat energy supplied to water is used to break the intermolecular forces between water molecules and convert the liquid into gas(steam). So, the heat is absorbed by water without rise in temperature, this heat is called latent heat of vaporization.

Q6. Take different matters from your surroundings and classify the matter in different ways and make a table as below-

 

Name of matter	Elements	Compound	Mixture
Mango shake			mixture

Write different points which differentiate elements, compounds and mixture.

Answer

We have taken different matters and classified them into the following table.

Q7. Imagin there is any matter say “Matter A”. “Matter A” can be compressed by applying pressure. “Matter A” expand with increase in temperature and contracts with decrease in temperature. Name and explain the nature of “Matter A”.

Answer

 

The matter ‘A’ is a gas.

Explanation

   1. Gases can be compressed by applying pressure because the particles in gases are far from each other due to weak attraction forces.

   

   2. Gases expand when heated and contract when cooled because particles gain or loss kinetic energy.

Nature of Matter ‘A’

The matter ‘A’ is gas. It has no fixed shape and volume. It fill the entire space of the container in which it is kept. Particles of gases are in motion. It is highly compressible.

Q8. In ancient time, when there was no water purifier, explain different methods to purify the water for drinking purpose used by our forefathers. Support your answer why these methods were used to purify the water.

Answer

In ancient times, our forefathers used simple and natural methods to purify water for drinking. These methods are based on traditional knowledge.

   1. Boiling

   2. Sedimentation and decantation

   3. Filtration

   4. Use of Alum(Fitkari)

   5. Storing in copper or earthen posts

   6. Use of Neem or Tulsi

   1. Boiling: Water was boiled for some time and this kills harmful bacteria and viruses and other microorganisms. Water obtained after boiling was safe for drinking.

   2. Sedimentation and decantation: This method removes visible impurities like sand and stones. Water is kept in vessels for some time and heavy impurities settle down at the bottom then the clean water was poured off from the top.

   3. Filtration: Water was passed through a cotton or muslin cloth. Solid particles and other dust particles were removed through this cloth.

   4. Use of Alum: Alum or fitkari was used to clean water. A piece of alum was stirred into the water. This helps in coagulating small suspended dust particles and make them settle down at the bottom.

   5. Storing in copper or earthen pots: Copper has naturel antibacterial properties and earthen pots helped cooling and filtration.

   6. Use of Neem and Tulsi : Neem and tulsi has antibacterial and medicinal properties that made water safer to drink.

These traditional methods were used to purify water in ancient times.

Q9. Observe your mother throughout the day and make a list when she is using different methods to purify or to separate substances or anything else. Explain anyone method used by her in detail.

Answer

My mother uses following methods to purify or separate substances.

    1. Filtering tea: Separate tea leaves from tea (filtration)

    2. Removing stones from pulses or grains: Pick impurities by hand (hand picking)

    3. Straining rice water: separate water after washing rice(decantation)

    4. Boling milk: This method is used for killing germs and bacteria present in milk (Heat treatment)

    5. Washing vegetables: For removing dirt and pesticides(cleaning)

Filtration

 Principle: This method is used to separate insoluble solid form liquid.

Process: When tea is ready, my mother pours the boiled tea through a sieve. The liquid pass through this but the tea leaves remain in the sieve. Tea leaves are solid and insoluble so that they cannot pass through the small holes of the sieve.

Q10. Make a mixture of “Iron + sugar+ sand” and another mixture of “lemon juice + sugar+ water”. Observe both the mixture and comment how mixtures are different in nature. Is it possible to separate both the mixtures? If yes, Name and explain method of separation. If not, support your answer with suitable reasons.

Answer

We have two mixtures (1) Iron+ sugar + sand (2) Lemon juice +sugar +water

Mixture 1 (Iron+ sugar + sand) : This is a heterogenous mixture. The components of heterogenous mixture can be seen easily. They do not dissolve into each other and their properties remain unchanged.

Mixture 2 (lemon juice + sugar + water) : This is a homogenous mixture. The components of homogenous mixture are uniformly mixed and cannot be seen separately.

Separation methods

Both mixtures can be separated. Mixture 1 can be separated by simple physical method and mixture 2 can be separated by complex separation method.

Separation of mixture 1 : First we use a magnet to separate iron particles, then we dissolve the remaining part which contains sugar and sand in water. Sugar gets dissolved in water now we filter to separate sand. Finaly we heat water so that water evaporates and sugar remains in solid form.

Separation of mixture 2: The components of this mixture cannot be separated at home by simple methods. We use evaporation and distillation to separate components.