(1) Solids have fixed shape and are rigid. Question 5. (i) Particles of matter have spaces between them. (c) Adil showed the value of intelligence, awareness, and self-responsibility. ‘ Hence we are able to sip hot tea or milk faster from a saucer rather than a cup. Answer: (a) The wet cloth gave the cooling effect to the pot, as the water in the cloth evaporated and evaporation causes cooling effect. Answer. The pressure of air is measured in atmosphere and pascal. (b) a fixed temperature Answer: (a) Difference in the characteristics of 3 states of matter. The smell of hot sizzling food reaches you several metres away, but to get the smell from cold food you have to go close. (a) 25°C (b) 373°C. Liquids and gases can be compressed but it is difficult to compress solids. Note: The sense of smell is not matter. But, if the temperature of the solid is increased, then the rate of diffusion of the solid particles into air increases. 11. Question 1. 25 + 273 = 298 K Cotton clothes because it has pores in it, which absorbs sweat and allows the sweat to evaporate faster thereby giving cooling effect. On hot and humid day, desert coolers are not effective as the air cannot hold any more moisture to get the cooling effect. Answer: Matter has 3 different states. Give two examples of diffusion. (a) 98°C (b) 100°C Question 15. What is dry ice? (d) all temperatures (b) We can get the smell of perfume sitting several metres away because perfume contain volatile solvent and diffuse faster and can reach people sitting several metres away. All Matter in Our Surroundings Exercise Questions with Solutions to help you … 12. Why does a desert cooler cool better on a hot dry day? To get fastest exam alerts and government job alerts in India, join our Telegram channel. Give reasons for the following observation: (b) two gases cannot diffuse into each other Question 2. (b) the molecules use the heat to overcome the force of attraction (b) What are the other two factors on which evaporation of water depends? Question 1. Why? It explains the cause of the happenings of sunrise, sunset, and changing of the seasons. Which of the following are matter? (c) 110°C (d) 90°C (b) 470 K into °C 470 – 273 = 197°C, Question 2. Why is water liquid at room temperature? Matter can exist in three physical states—solid, liquid, and gaseous. Adil parked his bicycle on a sunny day in a parking stand of his school campus. What type of clothes should we wear in summer? Download the NCERT Solutions app for quick access to NCERT Solutions Class 9 Science Chapter 1 Matter In Our Surroundings. (b) Why is air compressible? Why are we able to sip hot tea or milk faster from a saucer rather than a cup? NCERT Solutions for Class 9 Science are given for the students so that they can get to know the in text question and chapter end question answers in case they are not able to find it.It is important for all the students who are in Class 9th currently. is provided to make the study simple and interesting. Hence, the smell of hot sizzling food reaches us even at a distance, but to get the smell from cold food we have to go close. Question 4. (a) Naphthalene balls disappear with time without leaving any solid. Answer: Solid carbon dioxide obtained by cooling and applying pressure on carbon dioxide gas. You can also download. The molecules of this matter use heat to overcome the force of attraction between the particles, at this period of time, temperature remains constant. Answer: The water vapour present in air, comes in contact with the cold outer surface of the container thereby condensing it to form water droplets. Evaporation of a liquid occurs at (a) Why did the type burst? Anything that occupies space and has mass is called matter. Define latent heat of vaporization. Question 12. (3) a decrease in humidity, (a) freezing (b) condensation Answer: The earthen pot is porous with lot of pores on it, the water oozes out through these pores and the water gets evaporated at the surface of the pot thereby causing cooling effect. Ice at 0°C is more effective in cooling than water at the same temperature because Explain giving examples the various factors on which rate of evaporation depends. Question 9. (b) Tea in saucer cools faster than in a cup. Question 11. (a) Why did Sita keep wet cloth surrounding the earthen pot? Answer: Cotton has large number of pores, in which air is trapped. This water evaporates due to hot dry weather. If you are a student of class 9 who is using NCERT Textbook to study Maths, then you must come across chapter 1 Matter In Our Surroundings. Air and smell of perfume are gaseous states of matter. This extra heat is acquired by the molecules in the form of hidden heat called latent heat to change from one state of matter to the other state. Question 3. Answer: (a) 25°C is liquid (b) 0°C is solid or liquid Name the state of matter that have the tendency to maintain their shape when subjected to outside force. Hence, smell of perfume is matter. (c) temperature lower than boiling point (vi) Kinetic energy: The energy possessed by particles due to their motion is called kinetic energy. Answer: A diver is able to cut through water in a swimming pool. The density of water is maximum at (a) 1.0 1 32 5 x 105 Pa (b) 1.01325 x 104 Pa Question 8. (c) 4°C (d) 273 K Hence, the smell of hot sizzling food reaches us even at a distance, but to get the smell from cold food we have to go close. So the density of solids is generally more than that of the liquids and gases. Answer: Milk drops dissolved in water and perfume sprayed in a room. Subjects like Science, Maths, English will become easy to study if you have access to, , Maths solutions and solutions of other subjects. This solution contains questions, answers, images, step by step explanations of the complete Chapter 1 titled Matter in Our Surroundings of Science taught in class 9. This shows that the particles of water have intermolecular space and has less force of attraction. Topics and Sub Topics in Class 9 Science Chapter 1 Matter in Our Surroundings: These solutions are part of NCERT Solutions for Class 9 Science. Hence their density is more. Question 5. Define matter. However, the smell or odour of a substance is Classified as matter. (a) because water is a good solvent Convert the following temperatures to the Celsius scale. Question 15. dame any three substances that show sublimation. What are fluids? Find out why. Here on AglaSem Schools, you can access to NCERT Book Solutions in free pdf for Science for Class 9 so that you can refer them as and when required. Answer: The air holds water vapour, this air with water is called humid air and the phenomenon is called humidity. Answer: The atmospheric pressure at sea level is 1 atmosphere and taken as the normal atmospheric pressure. Question 3. Answer: The gases from the atmosphere diffuse and dissolve in water. The conversion of gas into liquid is called (a) What is CNG? (b) During summers, the CNG connections and cylinder need to be checked because the gas expands due to heat and if there would be any leakage then it would cause fire in the vehicle. However, the smell or odour of a substance is Classified as matter. Vedantu.com - No.1 online tutoring company in India provides you the Free PDF download of NCERT Solutions for Class 9 Science (Chemistry) Chapter 1 - Matter in Our Surroundings solved by Expert Teachers as per NCERT (CBSE) Book guidelines. Note: The sense of smell is not matter. The melting point of ice is 273.16 K. What does this mean? Question 4. Why is it advisable to use pressure cooker at higher altitudes? Transpiration is loss of water through small tiny pores of leaves called stomata. (ii) Particles of matter are continuously moving. Question 8. This cool air is sent in the room by the fan. (a) 293 K (b) 470 K. Water will evaporate faster in sun than in shade. Convert the following temperatures to the Kelvin scale. (4) an increase in wind speed. (2) Oxygen cylinders in the hospitals have compressed gas filled in it.