NCERT Solutions for Class 9 Science Chapter 1 Matter in Our Surroundings

Q:

What produces more severe burns, boiling water or steam?

A:

Steam contains more heat, in the form of latent heat, as compared to boiling water. So when steam comes in contact with skin it will give more heat than boiling water, so steam causes more severe burns.

Burns caused by steam are more severe than those caused by the boiling water; though both are at the same temperature (100 °C).This is because, steam has 540 kcal/kg (latent heat) more energy than boiling water. When steam condenses on skin, it gives out 540 kcal/kg more energy than the boiling water.

Q:

Convert the following temperatures to the Kelvin scale. (a) 25°C (b) 373°C

A:

Q:

Convert the following temperatures to the Celsius scale.
(a) 293 K (b) 470 K

A:

Q:

Why is ice at 273 K more effective in cooling than water at the same temperature?

A:

Ice is solid form of water which at its freezing point (273K) absorbs heat to get converted into liquid form at this constant temperature which is called the latent heat of fusion. When completely converted into water (liquid), it will absorb heat till its temperature becomes equal to that of the surrounding or the body to which it has contact.

But water at 273K will only absorb heat till its temperature becomes equal to that of the surrounding or the body to which it has contact.

Therefore, ice at 273 K more effective in cooling than water at the same temperature.

Q:

Give two reasons to justify—
(a) Water at room temperature is a liquid.
(b) an iron almirah is a solid at room temperature.

A:

(a) Water has no fixed shape but has a fixed volume that is,it occupies the shape of the container in which it is kept. Boiling point of water is 100°C and its freezing point is 0°C but the room temperature is between 0 and 100 0°C, therefore, it is a liquid at room temperature.
(b) All the atoms in iron are very tightly packed at the room temperature. Also its melting and boiling point is very high as it is a metal. So it is a solid at room temperature.

Q:

What is the physical state of water at—
(a) 25°C (b) 0°C (c) 100°C ?

A:

(a) At 25°C water exists as a liquid, with some water vapour above the water surface
(b) At 0°C water can exist as a solid as well as a liquid. Small amount of water vapour will be present in the air above the water/ice mixture.
(c) At 100°C water can exist in both liquid and gaseous states.

Q:

Arrange the following substances in increasing order of forces of attraction between the particles— water, sugar, oxygen.

A:

Oxygen is a gas; therefore, the force of attraction is negligible between its particles. Water is a liquid, so the force of attraction between its particles is more than liquid and less than solid. Since sugar is a solid, thus force of attraction between particles is greatest. Hence, the correct increasing order of forces of attraction between the particles is as follows

Oxygen < Water < Sugar

Q:

Give reason for the following observations.
(a) Naphthalene balls disappear with time without leaving any solid.
(b) We can get the smell of perfume sitting several metres away.

A:

(a) Naphthalene is a sublimating substance. Therefore, naphthalene balls sublimate that is turns into vapour without changing into liquid. Therefore, they disappear with time without leaving any solid.
(b) We can get the smell of perfume sitting several meters away because of diffusion. The molecules of perfume spread out through the air and reach to great distance.

Q:

Name A, B, C, D, E and F in the following diagram showing change in its state

A:

A. Fusion or melting
B. Vaporisation
C. Condensation
D. Solidification
E. Sublimation
F. Deposition

Benefits of NCERT Solutions

Following are some of the benefits of using NCERT Solutions by Extramarks.

1. They are developed by our experts with the right approach for precisely answering the textbook questions.

2. They are free of cost and available online to help class 9 students.

3. They not only explain every topic but also prepare students for further examinations. 

4. They are proven to be helpful to students in their exam preparation, homework and competitive exams.

5. They will help in understanding the solutions and the methodology of writing the answers in the exams.

Tips & Strategies for Class 9 Exam Preparation

1. Jot down important chapters or topics for your exam preparation.

2. Learn from the best teachers with Extramarks and clear your doubts instantly.

3. While practicing, refer to NCERT Solutions for class 9 to understand step-by-step solutions to all questions.

4. Solve as many sample papers as you can to prepare well for the exams.

5. Lastly, don’t panic. Try to meditate at least for 15 minutes every day- it will help you retain things better.

Why opt for Extramarks NCERT Solutions for Class 9 ?

Extramarks provide NCERT Solutions for all subjects at your fingertips. These solutions are designed by subject matter experts and provide solutions to every NCERT textbook questions. These solutions help students in their exam preparation and home assignments. We hope NCERT Solutions for class 9 will come in handy for every student and help them understand everything in a better way.

Frequently Asked Questions

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When to refer to NCERT Solutions for Class 9?

You can refer to NCERT solutions for class 9 anytime during your academic year. Whether you are preparing for class tests or unit tests or pre-board exams, you can refer to the class 9 NCERT solutions easily. The NCERT solutions are available on Extramarks - The Learning App and Extramarks website in the footer section.

What can I do to get better marks in Class 9?

If you want to gain good marks in Class 9 examination then we suggest that you go through NCERT books solutions for class 9 listed on the Extramarks website. The solutions are self-explanatory and written in easy to understand language so you can easily learn and ace your exams with the help of these solutions.

Why are the NCERT solutions Important for Class 9?

NCERT solutions class 9 are self-explanatory and form the basis of examination. Since the exam syllabus is taken directly out of the NCERT books, studying NCERT solutions becomes important to prepare for the exams.

What are some expert tips to score good marks in Class 9 CBSE?

If you want to score good marks in Class 9, follow these tips:

1. Study NCERT Solutions from Extramarks website.

2. Study using Extramarks - The Learning App, practice using the sample papers, and prepare through the interactive video modules.

3. Prepare a timetable and schedule your subjects and save time for revision.. Get concept clarity by tuning in to the Extramarks live classes.

How to Prepare for Competitive Exam Through NCERT Class 9 Solutions?

NCERT solutions for Class 9 science are amazingly useful for JEE and NEET and if you are preparing for any other competitive exam then consider studying through the NCERT solutions listed on the Extramarks website. You can also study the 9-10 and other classes syllabus on Extramarks - The Learning App.

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