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

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

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Access NCERT Solutions for Class 9 Science Chapter 1 – हमारे आस पास के पदार्थ part-1

Access NCERT Solutions for Class 9 Science Chapter 1 – हमारे आस पास के पदार्थ

अभ्यास

1. निम्नलिखित तापमान को सेल्सियस इकाई में परिवर्तित करें। 

(क) 300 K

उत्तरः तापमान °C इकाई में 

300 - 273 = 27 °C

(ख) 573 K

उत्तरः तापमान °C इकाई में

573 - 273 = 300 °C


2. निम्नलिखित तापमान को केल्विन इकाई में परिवर्तित करें 

(क) 25 °C

उत्तरः तापमान K इकाई में 

25 + 273 = 298 K

(ख) 373 °C  

उत्तरः तापमान K इकाई में

 373 + 273 = 646 K


3. निम्नलिखित अवलोकन हेतु कारण लिखिए: 

(क) नेफ़थलीन को रखा रहने देने पर यह समय के साथ कुछ भी ठोस पदार्थ छोड़े बिना अदृश्य हो जाती है।

उत्तरः नेफ़थलीन वाष्पशील ठोस  पदार्थ होने के कारण वाष्पीकृत होकर ठोस अवस्था से सीधा ही गैस में बदल जाती है, जिस कारण वह कुछ समय के बाद कुछ भी ठोस पदार्थ छोड़े बिना अदृश्य हो जाती है। इस प्रक्रिया को ऊर्ध्वपातन कहते है|

(ख) हमें इत्र की गंध  बहुत दूर बैठे हुए भी पहुँच जाती है।

उत्तरः इत्र भी एक वाष्पशील द्रव होता है यह तुरंत वाष्प में बदलकर वायु  में विसरित  हो जाता है, जिस कारण दूर बैठे हुए भी हमें उसकी सुगंध आ जाती है।यह घटना विसरण के परिणामस्वरूप होती है| 


4. निम्नलिखित पदार्थों को उनके कणों के बीच बढ़ते हुए आकर्षण के अनुसार व्यवस्थित करें: 

जल , चीनी , ऑक्सीजन

उत्तरः कणों के बीच बढ़ते आकर्षण का क्रम -

1.ऑक्सीजन

2. जल

3. चीनी


5. निम्नलिखित तापमान पर जल की भौतिक अवस्था क्या है|

 (क) 25 °C 

उत्तरः जल 25 °C पर द्रव अवस्था में पाया जाता है|

(ख) 0 °C 

 उत्तरः जल 0 °C पर  ठोस अवस्था में पाया जाता है|

(ग) 100 °C ? 

उत्तरः जल 100 °C पर गैसीय अवस्था में पाया जाता है । 


6. पुष्टि हेतु कारण दे :

(क) जल कमरे के ताप पर द्रव है।

उत्तरः जल कमरे के ताप पर द्रव होता है क्योंकि सामान्यत: कमरे का औसत तापमान  37  °C होता है। और हम जानते है कि जल 0 °C पर ठोस होता है एवं 100 °C पर वाष्पित हो जाता है। जबकि कमरे का सामान्य तापमान 20 से 25 °C होता है| कमरे का यह तापमान 0 °C से ज्यादा होने के कारण और 100 °C से कम होने के कारण  जल कमरे के ताप पर द्रव है|

(ख) लोहे की अलमारी कमरे के ताप पर ठोस 

उत्तरः लोहा बहुत अधिक कठोर होता है|जिस कारण इसका गलनांक बहुत अधिक होता है| गलनांक अधिक होने के कारण उसके पिघलने और पिघलकर द्रव बनने के लिए बहुत अधिक तापमान की आवश्यकता होती है। जबकि कमरे का ताप बहुत अधिक नहीं होता है |कमरे का तापमान लगभग 25 °C या इसके आस पास ही रहता है इसलिए  लोहे की अलमारी कमरे के ताप पर ठोस है|


7. 273 K पर बर्फ को ठंडा करने पर तथा जल को इसी तापमान पर ठंडा करने पर शीतलता का प्रभाव अधिक क्यों होता है?

उत्तरः 273 K पर जब बर्फ को ठंडा किया जाता है तब वह वायु में उपस्थित ऊष्मा को अवशोषित कर लेती है|ऊष्मा को अवशोषित कर लेने के कारण हमें  शीतलता का अनुभव होता है। जबकि उसी ताप पर जल को ठंडा करने पर वह वायु में उपस्थित  ऊष्मा को अवशोषित नहीं कर पाती  जिस कारण हमें शीतलता का अनुभव नहीं होता है । 


8. उबलते हुए जल अथवा भाप में से जलने की तीव्रता किसमें अधिक महसूस होती है।

उत्तरः उबलते हुए जल की अपेक्षा भाप में  जलने की तीव्रता अधिक महसूस होती है क्योंकि भाप में उपस्थित  कणों में जल में उपस्थित  कणों की तुलना में अधिक ऊर्जा पाई जाती है|पाई जाने वाली  यह अतिरिक्त ऊर्जा गुप्त ऊष्मा के रूप में होती है जिस कारण वे ज्यादा ऊष्मा उत्पन्न करते हैं|परिणामस्वरूप भाप से त्वचा पर ज्यादा जलन महसूस होती है| 


9. निम्नलिखित चित्र के लिए A, B, C, D, E, तथा F की अवस्था परिवर्तन को नामांकित करें:

(Image will be uploaded soon)

उत्तरः

A. संगलन

B. वाष्पीकरण

C. संघनन

D. जमाना

E. ऊर्ध्वपातन 

F.  निक्षेपण


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

Chapter-wise NCERT Solutions are provided everywhere on the internet with an aim to help the students to gain a comprehensive understanding. Class 9 Science Chapter 1 solution Hindi mediums are created by our in-house experts keeping the understanding ability of all types of candidates in mind. NCERT textbooks and solutions are built to give a strong foundation to every concept. These NCERT Solutions for Class 9 Science Chapter 1 in Hindi ensure a smooth understanding of all the concepts including the advanced concepts covered in the textbook.

NCERT Solutions for Class 9 Science Chapter 1 in Hindi medium PDF download are easily available on our official website (vedantu.com). Upon visiting the website, you have to register on the website with your phone number and email address. Then you will be able to download all the study materials of your preference in a click. You can also download the Class 9 Science Matter in Our Surroundings solution Hindi medium from Vedantu app as well by following the similar procedures, but you have to download the app from Google play store before doing that.

NCERT Solutions in Hindi medium have been created keeping those students in mind who are studying in a Hindi medium school. These NCERT Solutions for Class 9 Science Matter in Our Surroundings in Hindi medium pdf download have innumerable benefits as these are created in simple and easy-to-understand language. The best feature of these solutions is a free download option. Students of Class 9 can download these solutions at any time as per their convenience for self-study purpose.

These solutions are nothing but a compilation of all the answers to the questions of the textbook exercises. The answers/ solutions are given in a stepwise format and very well researched by the subject matter experts who have relevant experience in this field. Relevant diagrams, graphs, illustrations are provided along with the answers wherever required. In nutshell, NCERT Solutions for Class 9 Science in Hindi come really handy in exam preparation and quick revision as well prior to the final examinations.


FAQs (Frequently Asked Questions)

1. A diver can cut through water in a swimming pool. Which property of matter does this observation show?

A diver can easily dive into the water of a swimming pool because the arrangement of molecules in a liquid (water in this case) is not compact, which increases the intermolecular space. Liquids like water also show a weaker force of attraction between the molecules which is also a cause of increased intermolecular space in liquids. Due to the high intermolecular space in the water, a diver can cut through the water. 

2. Liquids generally have a lower density as compared to solids. But you must have observed that ice floats on water. Why?

If an object has a lower density than the density of a liquid, the object will float on the liquid. Solids have a higher density than liquids and that is precisely why solids float on water. But, ice is also solid, so it should float on water. But this is not the case because there are larger intermolecular spaces in ice as compared to water and that is why the density of ice is lower than the density of water. For more solutions from this chapter, visit the page NCERT Solutions for Class 9 Science Chapter 1 on the Vedantu website or download the Vedantu app to access these resources at free of cost.

3. What are the factors affecting evaporation?

Evaporation is a phenomenon in which a liquid changes into vapour at a temperature below its boiling point. Some factors affecting the evaporation are - 

  • An increase in surface area will lead to an increase in the rate of evaporation

  • An increase in temperature increases the kinetic energy in liquid particles increasing evaporation. 

  • Decrease in humidity: If moisture in the air is high, the rate of evaporation slows down. 

  • An increase in wind speed helps in decreasing the amount of moisture in the air.

4. How does evaporation cause cooling?

Evaporation causes cooling because when evaporation occurs the particles that are losing energy during the process tries to gain back energy from the particles around it. This absorption of energy from the near surroundings causes a cooling effect on the surrounding from where the energy is being absorbed. One example is the use of acetone on your palm. When you are applying the acetone, the particles of the liquid absorb energy from its surroundings and evaporate giving a cooling sensation. For more Solutions from this chapter, visit the page NCERT Solutions Class 9 Chapter 1.

5. Why should you wear cotton clothes during summer?

We should wear cotton clothes during summers because cotton is a very good material at absorbing water and exposing the water to the atmosphere where the particles in the liquid evaporate easily and these particles try to regain energy from the near surroundings causing a cooling effect on our bodies. So, the perspiration keeps us cool during summers and the cotton material facilitates the evaporation process even more.

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