Matter in Our Surroundings : āφāĻŽāĻžā§° āϚāĻžā§°āĻŋāĻ“āĻ•āĻžāώ⧰ āĻĒāĻĻāĻžā§°ā§āĻĨ : Question with Answer


1. āϤāϞ⧰ āϕ⧋āύāĻŦā§‹ā§° āĻĒāĻĻāĻžā§°ā§āĻĨ ?  Science 9th : Ass / Eng


āϚāϕ⧀, āĻŦāĻžāϝāĻŧ⧁, āĻŦāĻžāĻĻāĻžāĻŽ, āĻ āĻžāĻŖā§āĻĄāĻž-āĻĒāĻžāύ⧀āϝāĻŧ, āϏ⧁āĻ—āĻ¨ā§āϧāĻŋ āĻĻā§ā§°āĻŦā§āϝ⧰ āϏ⧁āĻŦāĻžāϏ, āĻĒā§ā§°ā§‡āĻŽ, āϘ⧃āĻŖāĻž, āϚāĻŋāĻ¨ā§āϤāĻž, āĻ āĻžāĻŖā§āĻĄāĻž, āĻ—ā§‹āĻ¨ā§āϧ 


Ans:āĻĒāĻĻāĻžā§°ā§āĻĨ: āϚāϕ⧀, āĻŦāĻžāϝāĻŧ⧁, āĻŦāĻžāĻĻāĻžāĻŽ, āĻ āĻžāĻŖā§āĻĄāĻž-āĻĒāĻžāύ⧀āϝāĻŧ, āϏ⧁āĻ—āĻ¨ā§āϧāĻŋ āĻĻā§ā§°āĻŦā§āϝ⧰ āϏ⧁āĻŦāĻžāϏ, āĻĒāĻĻāĻžā§°ā§āĻĨ āύāĻšāϝāĻŧ: āĻĒā§ā§°ā§‡āĻŽ, āϘ⧃āĻŖāĻž, āϚāĻŋāĻ¨ā§āϤāĻž, āĻ āĻžāĻŖā§āĻĄāĻž, āĻ—ā§‹āĻ¨ā§āϧ


āĻ•āĻžā§°āĻŖ: āϝāĻŋāĻŦā§‹ā§° āĻŦāĻ¸ā§āϤ⧁⧰ āĻ­ā§° āĻĨāĻžāϕ⧇ āφ⧰⧁ āĻ āĻžāχ āϞāϝāĻŧ, āϏ⧇āχāĻŦā§‹ā§° āĻĒāĻĻāĻžā§°ā§āĻĨāĨ¤ āĻ…āύ⧁āĻ­ā§‚āϤāĻŋ āφ⧰⧁ āϧāĻžā§°āĻŖāĻž āĻĒāĻĻāĻžā§°ā§āĻĨ āύāĻšāϝāĻŧāĨ¤


1. Which of the following are matter ?


Chair, Air, Love, Smell, Hate, Peanuts, Thoughts, Cold, Cold drink, Fragrance of perfume


 Ans: Matter: Chair, Air, Peanuts, Cold drink, Fragrance of perfume. Not Matter: Love, Hate, Thoughts, Cold, Smell


Reason: Matter has mass and occupies space. Feelings and ideas are not physical substances.


2. āωāĻ¤ā§āϤāĻĒā§āϤ āĻŦāĻ¸ā§āϤ⧁⧰ āĻ—ā§‹āĻ¨ā§āϧ āĻĻā§‚ā§°āϞ⧈ āĻ•āĻŋāϝāĻŧ āϝāĻžāϝāĻŧ ?


Ans: āωāĻ¤ā§āϤāĻĒā§āϤ āĻŦāĻ¸ā§āϤ⧁⧰ āĻ—ā§‹āĻ¨ā§āϧ āĻĻā§‚ā§°āϞ⧈ āϝāĻžāϝāĻŧ āĻ•āĻžā§°āĻŖ āωāĻˇā§āĻŖāϤāĻž āĻŦāĻžāĻĸāĻŧāĻŋāϞ⧇ āĻ•āĻŖāĻŋāĻ•āĻžāĻŦā§‹ā§°ā§° āĻ—āϤāĻŋ āĻŦāĻžāĻĸāĻŧ⧇ āφ⧰⧁ āĻŦā§āϝāĻžāĻĒāύ (diffusion) āĻĻā§āϰ⧁āϤ āĻšāϝāĻŧāĨ¤


2. Why smell spreads faster in hot objects ?


Ans: Smell spreads faster from hot objects because higher temperature increases particle motion, which increases diffusion rate.


3. āĻĄā§āĻŦāĻžā§°ā§ā§ąā§‡ āĻĒāĻžāύ⧀ āĻĢāĻžāϞāĻŋ āϕ⧇āύ⧇āĻ•ā§ˆ āϏ⧋āĻŽāĻžāĻŦ āĻĒāĻžā§°ā§‡ ? 


Ans: āĻĄā§āĻŦāĻžā§°ā§ā§ąā§‡ āĻĒāĻžāύ⧀ āĻĢāĻžāϞāĻŋ āϏ⧋āĻŽāĻžāĻŦ āĻĒāĻžā§°ā§‡ āĻ•āĻžā§°āĻŖ āĻĒāĻžāύ⧀⧰ āĻ•āĻŖāĻŋāĻ•āĻžā§° āĻŽāĻžāϜāϤ āĻĢāĻžāρāĻ• āĻĨāĻžāϕ⧇ āφ⧰⧁ āϏāĻŋāĻšāρāϤ āϏāĻšāĻœā§‡ āϏ⧰āĻ•āĻŋ āϝāĻžāϝāĻŧāĨ¤


3. Why can a diver pass through water ?


Ans:A diver can pass through water because water particles have spaces between them and can easily move aside.


4. āĻĒāĻĻāĻžā§°ā§āĻĨā§° āĻ•āĻŖāĻŋāĻ•āĻžā§° āĻŦ⧈āĻļāĻŋāĻˇā§āĻŸā§āϝāϏāĻŽā§‚āĻš āĨ¤


Ans: 1. āĻ…āϤāĻŋ āĻ•ā§āώ⧁āĻĻā§ā§° āĻ•āĻŖāĻŋāĻ•āĻž  2. āĻŽāĻžāϜāϤ āĻĢāĻžāρāĻ• āĻĨāĻžāϕ⧇  3. āϏāĻĻāĻžāϝāĻŧ āĻ—āϤāĻŋ āϕ⧰⧇  4. āφāĻ•āĻ°ā§āώāĻŖ āĻŦāϞ āĻĨāĻžāϕ⧇  5. āωāĻˇā§āĻŖāϤāĻžāϤ āĻ—āϤāĻŋ āĻŦāĻžāĻĸāĻŧ⧇


4. Characteristics of particles of matter.


Ans: 1. Very small particles  2. Have space between them  3. Always in motion  4. Attract each other  5. Speed increases with temperature


============================================== Science 9th : Ass / Eng


1. āϤāϞ⧰ āĻĒāĻĻāĻžā§°ā§āĻĨāĻŦā§‹ā§° āϘāύāĻ¤ā§āĻŦā§° āĻŠā§°ā§āĻ§ā§āĻŦāĻ•ā§āϰāĻŽāϤ āϏāĻœā§‹ā§ąāĻžāĨ¤ (Arrange the following substances in increasing order of density.)


āĻŦāĻžāϝāĻŧ⧁, āϚāĻŋāĻŽāύāĻŋā§° āĻĒā§°āĻž āĻ“āĻ˛ā§‹ā§ąāĻž āϧ⧋āĻā§ąāĻž, āĻŽā§Œ, āĻĒāĻžāύ⧀, āϚāĻ•āĻŽāĻžāϟāĻŋ, āĻ•āĻĒāĻžāĻš āφ⧰⧁ āϞ⧋āĨ¤ (Air, smoke from chimney, honey, water, chalk, cotton and iron.)


āωāĻ¤ā§āϤ⧰ / AnsāϚāĻŋāĻŽāύāĻŋā§° āĻĒā§°āĻž āĻ“āĻ˛ā§‹ā§ąāĻž āϧ⧋āĻā§ąāĻž < āĻŦāĻžāϝāĻŧ⧁ < āĻ•āĻĒāĻžāĻš < āĻĒāĻžāύ⧀ < āĻŽā§Œ < āϚāĻ•āĻŽāĻžāϟāĻŋ < āϞ⧋ (Smoke from chimney < Air < Cotton < Water < Honey < Chalk < Iron)


2(a). āĻĒāĻĻāĻžā§°ā§āĻĨā§° āĻŦāĻŋāĻ­āĻŋāĻ¨ā§āύ āĻ…ā§ąāĻ¸ā§āĻĨāĻžā§° āĻŦ⧈āĻļāĻŋāĻˇā§āĻŸā§āϝāĻŦā§‹ā§°ā§° āĻĒāĻžā§°ā§āĻĨāĻ•ā§āϝ āĻĻ⧇āĻ–ā§ā§ąāĻžāχ āĻāĻ–āύ āϤāĻžāϞāĻŋāĻ•āĻž āϕ⧰āĻžāĨ¤ (Differentiate between the three states of matter.)


āωāĻ¤ā§āϤ⧰ / Ans:  āĻ•āĻ āĻŋāύ āĻĒāĻĻāĻžā§°ā§āĻĨā§° āύāĻŋāĻ°ā§āĻĻāĻŋāĻˇā§āϟ āφāĻ•ā§ƒāϤāĻŋ āφ⧰⧁ āĻ†ā§ŸāϤāύ āĻĨāĻžāϕ⧇āĨ¤ āϜ⧁āĻ˛ā§€ā§ŸāĻž āĻĒāĻĻāĻžā§°ā§āĻĨā§° āύāĻŋāĻ°ā§āĻĻāĻŋāĻˇā§āϟ āĻ†ā§ŸāϤāύ āφāϛ⧇ āĻ•āĻŋāĻ¨ā§āϤ⧁ āφāĻ•ā§ƒāϤāĻŋ āύāĻžāχāĨ¤ āϗ⧇āĻ›ā§€ā§Ÿ āĻĒāĻĻāĻžā§°ā§āĻĨā§° neither āύāĻŋāĻ°ā§āĻĻāĻŋāĻˇā§āϟ āφāĻ•ā§ƒāϤāĻŋ nor āĻ†ā§ŸāϤāύ āĻĨāĻžāϕ⧇āĨ¤ āĻ•āĻ āĻŋāύ⧰ āĻ•āĻŖāĻŋāĻ•āĻžāĻŦā§‹ā§° āϘāύāĻ•ā§ˆ āϏāĻœā§āϜāĻŋāϤ āĻĨāĻžāϕ⧇, āϜ⧁āĻ˛ā§€ā§ŸāĻžāϤ āĻŽāĻ§ā§āϝāĻŽā§€ā§ŸāĻž āφ⧰⧁ āϗ⧇āĻ›ā§€ā§ŸāϤ āĻŦāĻšā§āϤ āĻĻā§‚ā§°āϤ āĻĨāĻžāϕ⧇āĨ¤ āϗ⧇āϛ⧰ āĻ—āϤāĻŋāĻļāĻ•ā§āϤāĻŋ āφāϟāĻžāχāϤāĻ•ā§ˆ āĻŦ⧇āĻ›āĻŋāĨ¤


Solids have fixed shape and fixed volume. Liquids have fixed volume but no fixed shape. Gases have neither fixed shape nor fixed volume. The particles in solids are closely packed, in liquids moderately spaced, and in gases far apart. Gases have the highest kinetic energy.


2(b). āϤāϞ⧰ āĻŦāĻŋāώ⧟āĻŦā§‹ā§°ā§° āĻ“āĻĒā§°āϤ āĻŽāĻ¨ā§āϤāĻŦā§āϝ āĻĻāĻŋ⧟āĻžāĨ¤ (Comment on the following.)


āĻĻā§ƒā§āϤāĻž (Rigidity): āĻ•āĻ āĻŋāύ āĻĒāĻĻāĻžā§°ā§āĻĨ āϏāĻšāĻœā§‡ āφāĻ•ā§ƒāϤāĻŋ āϏāϞāύāĻŋ āύāϕ⧰⧇āĨ¤ (Solids cannot change shape easily.)


āϏāĻ‚āϕ⧋āϚāύāĻļā§€āϞāϤāĻž (Compressibility): āϗ⧇āĻ› āϏāĻšāĻœā§‡ āϏāĻ‚āϕ⧁āϚāĻŋāϤ āϕ⧰āĻŋāĻŦ āĻĒāĻžā§°āĻŋ, āĻ•āĻŋāĻ¨ā§āϤ⧁ āĻ•āĻ āĻŋāύ āϏāĻšāĻœā§‡ āϏāĻ‚āϕ⧁āϚāĻŋāϤ āύāĻšā§ŸāĨ¤ (Gases can be compressed easily, but solids cannot.)


āĻĒā§āϰāĻŦāĻžāĻšāĻŋāϤāĻž (Fluidity): āϜ⧁āĻ˛ā§€ā§ŸāĻž āφ⧰⧁ āϗ⧇āĻ›ā§€ā§Ÿ āĻĒāĻĻāĻžā§°ā§āĻĨ āĻŦ⧈ āϝāĻžāĻŦ āĻĒāĻžā§°ā§‡āĨ¤ (Liquids and gases can flow.)


āφāĻ•āĻžā§° (Shape): āĻ•āĻ āĻŋāύ⧰ āύāĻŋāĻ°ā§āĻĻāĻŋāĻˇā§āϟ āφāĻ•āĻžā§° āĻĨāĻžāϕ⧇, āĻ•āĻŋāĻ¨ā§āϤ⧁ āϜ⧁āĻ˛ā§€ā§ŸāĻž āφ⧰⧁ āϗ⧇āĻ›ā§€ā§Ÿā§° āύāĻžāĻĨāĻžāϕ⧇āĨ¤ (Solids have fixed shape, but liquids and gases do not have fixed shape.)


āĻ—āϤāĻŋāĻļāĻ•ā§āϤāĻŋ (Kinetic Energy): āϗ⧇āϛ⧰ āĻ•āĻŖāĻŋāĻ•āĻžāĻŦā§‹ā§°ā§° āĻ—āϤāĻŋāĻļāĻ•ā§āϤāĻŋ āφāϟāĻžāχāϤāĻ•ā§ˆ āĻŦ⧇āĻ›āĻŋāĨ¤ (Gas particles have the highest kinetic energy.)


āϘāύāĻ¤ā§āĻŦ (Density): āĻ•āĻ āĻŋāύ āĻĒāĻĻāĻžā§°ā§āĻĨā§° āϘāύāĻ¤ā§āĻŦ āϏāĻžāϧāĻžā§°āĻŖāϤ⧇ āĻŦ⧇āĻ›āĻŋāĨ¤ (Solids generally have high density.)


3(a). āϕ⧋āύ⧋ āĻāϟāĻž āĻŦāĻ¨ā§āϧ āĻĒāĻžāĻ¤ā§ā§°āϤ āϗ⧇āĻ› ā§°āĻžāĻ–āĻŋāϞ⧇ āϏ⧇āχ āϗ⧇āϛ⧇ āĻĒāĻžāĻ¤ā§ā§°āĻŸā§‹ā§° āϏāĻ•āϞ⧋ āĻ…āĻ‚āĻļ āĻ…āϧāĻŋāĻ•āĻžā§° āϕ⧰⧇ āĻ•āĻŋ⧟ ? (Why does gas occupy the whole container ?)


āωāĻ¤ā§āϤ⧰ / Ans: āϗ⧇āϛ⧰ āĻ•āĻŖāĻŋāĻ•āĻžāĻŦā§‹ā§°ā§° āĻŽāĻžāϜāϤ āĻ…āϧāĻŋāĻ• āĻĢāĻžāρāĻ• āĻĨāĻžāϕ⧇ āφ⧰⧁ āϏāĻŋāĻšāρāϤ āϏāĻ•āϞ⧋ āĻĻāĻŋāĻļāϤ āĻ¸ā§āĻŦāĻžāϧ⧀āύāĻ­āĻžā§ąā§‡ āĻ—āϤāĻŋ āϕ⧰⧇āĨ¤ āĻ¸ā§‡ā§Ÿā§‡ āϗ⧇āϛ⧇ āĻĒāĻžāĻ¤ā§ā§°āĻŸā§‹ā§° āϏāĻ•āϞ⧋ āĻ…āĻ‚āĻļ āĻ…āϧāĻŋāĻ•āĻžā§° āϕ⧰⧇āĨ¤ (Gas particles have large spaces between them and move freely in all directions. Therefore, gas occupies the whole container.)


3(b). āϧāĻžā§°āĻ• āĻĒāĻžāĻ¤ā§ā§°ā§° āĻŦ⧇⧰āϤ āϗ⧇āϛ⧇ āϚāĻžāĻĒ āĻĻāĻŋā§Ÿā§‡ āĻ•āĻŋ⧟ ? (Why does gas exert pressure on the walls of the container ?)


āωāĻ¤ā§āϤ⧰ / Ans: āϗ⧇āϛ⧰ āĻ•āĻŖāĻŋāĻ•āĻžāĻŦā§‹ā§° āϏāĻĻāĻžā§Ÿ āĻ—āϤāĻŋ āϕ⧰āĻŋ āĻĨāĻžāϕ⧇ āφ⧰⧁ āĻĒāĻžāĻ¤ā§ā§°ā§° āĻŦ⧇⧰āϤ āϖ⧁āĻ¨ā§āĻĻāĻž āĻŽāĻžā§°ā§‡āĨ¤ āĻāχ āϖ⧁āĻ¨ā§āĻĻāĻžā§° āĻĢāϞāϤ⧇āχ āϚāĻžāĻĒ āĻ‰ā§ŽāĻĒāĻ¨ā§āύ āĻšā§ŸāĨ¤ (Gas particles continuously move and collide with the walls of the container. These collisions produce pressure.)


3(c). āĻ•āĻžāĻ ā§° āĻŸā§‡āĻŦ⧁āϞ āĻāĻ–āύāĻ• āĻ•āĻ āĻŋāύ āĻĒāĻĻāĻžā§°ā§āĻĨ āĻŦ⧁āϞāĻŋāĻŦ āĻĒāĻžā§°āĻŋ āĻ•āĻŋ⧟ ? (Why is a wooden table called a solid ?)


āωāĻ¤ā§āϤ⧰ / Ans: āĻ•āĻžāĻ ā§° āĻŸā§‡āĻŦ⧁āϞ⧰ āύāĻŋāĻ°ā§āĻĻāĻŋāĻˇā§āϟ āφāĻ•āĻžā§° āφ⧰⧁ āĻ†ā§ŸāϤāύ āφāϛ⧇āĨ¤ āĻ‡ā§ŸāĻžā§° āĻ•āĻŖāĻŋāĻ•āĻžāĻŦā§‹ā§° āϘāύāĻ•ā§ˆ āϏāĻœā§āϜāĻŋāϤ āĻĨāĻžāϕ⧇āĨ¤ āĻ¸ā§‡ā§Ÿā§‡ āχ āĻ•āĻ āĻŋāύ āĻĒāĻĻāĻžā§°ā§āĻĨāĨ¤ (A wooden table has fixed shape and fixed volume. Its particles are closely packed. Therefore, it is a solid.)


3(d). āĻŦāĻžāϝāĻŧ⧁āϤ āφāĻŽāĻžā§° āĻšāĻžāϤ āϏāĻšāĻœā§‡ āϘ⧁⧰āĻžāĻŦ āĻĒāĻžā§°ā§‹ āĻ•āĻŋāĻ¨ā§āϤ⧁ āĻ•āĻžāĻ ā§° āĻŽāĻžāĻœā§‡ā§°ā§‡ āĻ¨ā§‹ā§ąāĻžā§°ā§‹ āĻ•āĻŋ⧟ ? (Why can we move our hand easily in air but not through wood ?)


āωāĻ¤ā§āϤ⧰ / Ans: āĻŦāĻžāϝāĻŧ⧁⧰ āĻ•āĻŖāĻŋāĻ•āĻžāĻŦā§‹ā§°ā§° āĻŽāĻžāϜāϤ āĻ…āϧāĻŋāĻ• āĻĢāĻžāρāĻ• āĻĨāĻžāϕ⧇āĨ¤ āĻ•āĻŋāĻ¨ā§āϤ⧁ āĻ•āĻžāĻ ā§° āĻ•āĻŖāĻŋāĻ•āĻžāĻŦā§‹ā§° āϘāύāĻ•ā§ˆ āϏāĻœā§āϜāĻŋāϤ āĻĨāĻžāϕ⧇āĨ¤ āĻ¸ā§‡ā§Ÿā§‡ āĻŦāĻžāϝāĻŧ⧁āϤ āĻšāĻžāϤ āϏāĻšāĻœā§‡ āϘ⧁⧰āĻžāĻŦ āĻĒāĻžā§°ā§‹ āĻ•āĻŋāĻ¨ā§āϤ⧁ āĻ•āĻžāĻ ā§° āĻŽāĻžāĻœā§‡ā§°ā§‡ āĻ¨ā§‹ā§ąāĻžā§°ā§‹āĨ¤ (Air particles have large spaces between them, whereas wood particles are tightly packed. Therefore, we can move our hand easily in air but not through wood.)


4. āĻŦā§°āĻĢ āĻĒāĻžāύ⧀āϤ āĻ“āĻĒāĻ™āĻŋ āĻĨāĻžāϕ⧇ āĻ•āĻŋ⧟ ? (Why does ice float on water ?)


āωāĻ¤ā§āϤ⧰ / Ans: āĻŦā§°āĻĢā§° āϘāύāĻ¤ā§āĻŦ āĻĒāĻžāύ⧀āϤāĻ•ā§ˆ āĻ•āĻŽāĨ¤ āĻ¸ā§‡ā§Ÿā§‡ āĻŦā§°āĻĢ āĻĒāĻžāύ⧀⧰ āĻ“āĻĒā§°āϤ āĻ“āĻĒāĻ™āĻŋ āĻĨāĻžāϕ⧇āĨ¤ (Ice is less dense than water. Therefore, ice floats on water.)


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Introduction to Matter : āφāĻŽāĻžā§° āϚāĻžā§°āĻŋāĻ“āĻ•āĻžāώ⧰ āĻĒāĻĻāĻžā§°ā§āĻĨ - āĻ…āĻ‚āĻļ ā§§ : āĻĒāĻĻāĻžā§°ā§āĻĨā§° āĻĒā§°āĻŋāϚāϝāĻŧ


What is Matter ? :: āĻĒāĻĻāĻžā§°ā§āĻĨ āĻ•āĻŋ ?      Science 9th : Ass / Eng


Matter is anything that has mass and occupies space.āϝāĻŋ āĻŦāĻ¸ā§āϤ⧁⧰ āĻ­ā§° (mass) āφāϛ⧇ āφ⧰⧁ āĻ¸ā§āĻĨāĻžāύ āĻĻāĻ–āϞ āϕ⧰⧇, āϤāĻžāĻ• āĻĒāĻĻāĻžā§°ā§āĻĨ āĻŦā§‹āϞāĻž āĻšāϝāĻŧāĨ¤


Examples of Matter :: āĻĒāĻĻāĻžā§°ā§āĻĨā§° āωāĻĻāĻžāĻšā§°āĻŖ



  • Ice cube - has mass and shape. āĻŦā§°āĻĢā§° āϟ⧁āϕ⧁⧰āĻž - āĻ­ā§° āφ⧰⧁ āφāĻ•āĻžā§° āφāϛ⧇

  • Wooden block - occupies space. āĻ•āĻžāĻ ā§° āϟ⧁āϕ⧁⧰āĻž - āĻ¸ā§āĻĨāĻžāύ āĻĻāĻ–āϞ āϕ⧰⧇

  • Air in balloon - air also has mass. āĻŦ⧇āϞ⧁āύāϤ āĻĨāĻ•āĻž āĻŦāĻžāϝāĻŧ⧁ - āĻŦāĻžāϝāĻŧ⧁⧰⧋ āĻ­ā§° āĻĨāĻžāϕ⧇


Conclusion / āϏāĻŋāĻĻā§āϧāĻžāĻ¨ā§āϤ: Solid, liquid, and gas - all are matter. āĻ•āĻ āĻŋāύ āĻŦāĻž āĻ—ā§‹āϟāĻž, āĻĻā§ā§°ā§ą āφ⧰⧁ āϗ⧇āĻ› - āϏāĻ•āϞ⧋ āĻĒāĻĻāĻžā§°ā§āĻĨāĨ¤


Characteristics of Matter :: āĻĒāĻĻāĻžā§°ā§āĻĨā§° āĻŦ⧈āĻļāĻŋāĻˇā§āĻŸā§āϝāϏāĻŽā§‚āĻš


Matter has some special properties.āĻĒāĻĻāĻžā§°ā§āĻĨā§° āĻ•āĻŋāϛ⧁āĻŽāĻžāύ āĻŦāĻŋāĻļ⧇āώ āϗ⧁āĻŖ āφāϛ⧇āĨ¤


1. Matter is made up of tiny particles :: āĻĒāĻĻāĻžā§°ā§āĻĨ āϏ⧰⧁ āϏ⧰⧁ āĻ•āĻŖāĻžā§°ā§‡ āĻ—āĻ āĻŋāϤ : All matter is made of very tiny particles which we cannot see with naked eyes. āϏāĻ•āϞ⧋ āĻĒāĻĻāĻžā§°ā§āĻĨ āĻ…āϤāĻŋ āϏ⧰⧁ āϏ⧰⧁ āĻ•āĻŖāĻžā§°ā§‡ āĻ—āĻ āĻŋāϤ, āϝāĻŋāĻŦā§‹ā§° āĻ–āĻžāϞ⧀ āϚāϕ⧁āϤ āĻĻ⧇āĻ–āĻž āύāĻžāϝāĻžāϝāĻŧāĨ¤


2. Particles of Matter are Very Small. āĻĒāĻĻāĻžā§°ā§āĻĨā§° āĻ•āĻŖāĻžāĻŦā§‹ā§° āĻ…āϤāĻŋ āϏ⧰⧁ : Particles are extremely small in size (microscopic).āĻĒāĻĻāĻžā§°ā§āĻĨā§° āĻ•āĻŖāĻžāĻŦā§‹ā§° āĻ…āϤāĻŋ āϏ⧰⧁ (āĻ…āϪ⧁āĻŦā§€āĻ•ā§āώāĻŖāĻŋāĻ•) āφāĻ•āĻžā§°ā§°āĨ¤


3. Particles of Matter are in Constant Motion.āĻĒāĻĻāĻžā§°ā§āĻĨā§° āĻ•āĻŖāĻžāĻŦā§‹ā§° āϏāĻĻāĻžāϝāĻŧ āĻ—āϤāĻŋ āϕ⧰āĻŋ āĻĨāĻžāϕ⧇ : Particles are always moving. This motion increases on heating.āĻĒāĻĻāĻžā§°ā§āĻĨā§° āĻ•āĻŖāĻžāĻŦā§‹ā§° āϏāĻĻāĻžāϝāĻŧ āϚāϞāĻŽāĻžāύ āĻ…ā§ąāĻ¸ā§āĻĨāĻžāϤ āĻĨāĻžāϕ⧇āĨ¤ āĻ—ā§°āĻŽ āĻĻāĻŋāϞ⧇ āĻ—āϤāĻŋ āĻŦ⧃āĻĻā§āϧāĻŋ āĻĒāĻžāϝāĻŧāĨ¤


4. Particles of Matter Attract Each Other. āĻĒāĻĻāĻžā§°ā§āĻĨā§° āĻ•āĻŖāĻžāĻŦ⧋⧰⧇ āĻĒā§°āĻ¸ā§āĻĒā§°āĻ• āφāĻ•ā§°ā§āώāĻŖ āϕ⧰⧇ : There is a force of attraction between particles which holds them together. āĻ•āĻŖāĻžāĻŦā§‹ā§°ā§° āĻŽāĻžāϜāϤ āφāĻ•ā§°ā§āώāĻŖ āĻļāĻ•ā§āϤāĻŋ āĻĨāĻžāϕ⧇, āϝāĻŋāϝāĻŧ⧇ āϏāĻŋāĻšāρāϤāĻ• āĻāϕ⧇āϞāϗ⧇ āϧ⧰āĻŋ ā§°āĻžāϖ⧇āĨ¤


Microscopic Concepts :: āĻ…āϪ⧁āĻŦā§€āĻ•ā§āώāĻŖāĻŋāĻ• āϧāĻžā§°āĻŖāĻž



  • Microscopic particles: Cannot be seen by naked eyes. āĻ…āϪ⧁āĻŦā§€āĻ•ā§āώāĻŖāĻŋāĻ• āĻ•āĻŖāĻž: āĻ–āĻžāϞ⧀ āϚāϕ⧁āϤ āĻĻ⧇āĻ–āĻž āύāĻžāϝāĻžāϝāĻŧ

  • Particles moving: Shows kinetic energy. āĻ•āĻŖāĻžā§° āĻ—āϤāĻŋ: āĻ—āϤāĻŋāĻļāĻ•ā§āϤāĻŋ āĻŦ⧁āϜāĻžāϝāĻŧ

  • Force of attraction: Keeps matter together. āφāĻ•ā§°ā§āώāĻŖ āĻļāĻ•ā§āϤāĻŋ: āĻĒāĻĻāĻžā§°ā§āĻĨ āĻāϕ⧇āϞāϗ⧇ ā§°āĻžāϖ⧇


States of Matter :: āĻĒāĻĻāĻžā§°ā§āĻĨā§° āĻ…ā§ąāĻ¸ā§āĻĨāĻžāϏāĻŽā§‚āĻš :- 


Matter exists in three states.āĻĒāĻĻāĻžā§°ā§āĻĨ āĻŽā§‚āϞāϤāσ āϤāĻŋāύāĻŋāϟāĻž āĻ…ā§ąāĻ¸ā§āĻĨāĻžāϤ āĻĒā§‹ā§ąāĻž āϝāĻžāϝāĻŧāĨ¤


Solid : āĻ•āĻ āĻŋāύ āĻŦāĻž āĻ—ā§‹āϟāĻž Fixed shape : āύāĻŋā§°ā§āĻĻāĻŋāĻˇā§āϟ āφāĻ•āĻžā§°, Fixed volume : āύāĻŋā§°ā§āĻĻāĻŋāĻˇā§āϟ āφāϝāĻŧāϤāύ


Ex: Stone, Ice, āωāĻĻāĻžāĻšā§°āĻŖ: āĻĒāĻžāĻĨā§°, āĻŦā§°āĻĢ


Liquid (āĻĻā§ā§°ā§ą): 1. No fixed shape - āύāĻŋā§°ā§āĻĻāĻŋāĻˇā§āϟ āφāĻ•āĻžā§° āύāĻžāχ 2. Fixed volume - āύāĻŋā§°ā§āĻĻāĻŋāĻˇā§āϟ āφāϝāĻŧāϤāύ āφāϛ⧇


Ex: Water, Milk, āωāĻĻāĻžāĻšā§°āĻŖ: āĻĒāĻžāύ⧀, āĻĻ⧁āϧ


Gas (āϗ⧇āĻ›) : No fixed shape : āύāĻŋā§°ā§āĻĻāĻŋāĻˇā§āϟ āφāĻ•āĻžā§° āύāĻžāχ, No fixed volume : āύāĻŋā§°ā§āĻĻāĻŋāĻˇā§āϟ āφāϝāĻŧāϤāύ āύāĻžāχ


Ex: Air, Oxygen, āωāĻĻāĻžāĻšā§°āĻŖ: āĻŦāĻžāϝāĻŧ⧁, āĻ…āĻ•ā§āϏāĻŋāĻœā§‡āύ


Exam Tips : āĻĒā§°ā§€āĻ•ā§āώāĻžā§° āĻŦāĻžāĻŦ⧇ āĻāĻ•āĻļāĻžā§°ā§€ āϏāĻžā§°āĻžāĻ‚āĻļ 



  • Matter has mass, occupies space, and exists as solid, liquid, and gas.

  • āĻĒāĻĻāĻžā§°ā§āĻĨā§° āĻ­ā§° āφāϛ⧇, āĻ¸ā§āĻĨāĻžāύ āĻĻāĻ–āϞ āϕ⧰⧇ āφ⧰⧁ āĻ•āĻ āĻŋāύ āĻŦāĻž āĻ—ā§‹āϟāĻž, āĻĻā§ā§°ā§ą, āϗ⧇āĻ› ā§°ā§‚āĻĒ⧇ āĻĒā§‹ā§ąāĻž āϝāĻžāϝāĻŧāĨ¤


What is Matter ? :: āĻĒāĻĻāĻžā§°ā§āĻĨ āĻ•āĻŋ ? : Click Here


Questions & Answers - āĻĒā§ā§°āĻļā§āύ āφ⧰⧁ āωāĻ¤ā§āϤ⧰


1) Define matter. Give two examples.āĻĒāĻĻāĻžā§°ā§āĻĨā§° āϏāĻ‚āĻœā§āĻžāĻž āĻĻāĻŋāϝāĻŧāĻžāĨ¤ āĻĻ⧁āχāϟāĻž āωāĻĻāĻžāĻšā§°āĻŖ āĻĻāĻŋāϝāĻŧāĻžāĨ¤


Ans / āωāĻ¤ā§āϤ⧰: Matter is anything that has mass and occupies space. Examples: Ice cube, Wooden block. āϝāĻŋ āĻŦāĻ¸ā§āϤ⧁⧰ āĻ­ā§° āĻĨāĻžāϕ⧇ āφ⧰⧁ āĻ¸ā§āĻĨāĻžāύ āĻĻāĻ–āϞ āϕ⧰⧇ āϤāĻžāĻ• āĻĒāĻĻāĻžā§°ā§āĻĨ āĻŦā§‹āϞāĻž āĻšāϝāĻŧāĨ¤ āωāĻĻāĻžāĻšā§°āĻŖ: āĻŦā§°āĻĢā§° āϟ⧁āϕ⧁⧰āĻž, āĻ•āĻžāĻ ā§° āϟ⧁āϕ⧁⧰āĻžāĨ¤


2) What are the three states of matter? Give one example of each. āĻĒāĻĻāĻžā§°ā§āĻĨā§° āϤāĻŋāύāĻŋāϟāĻž āĻ…ā§ąāĻ¸ā§āĻĨāĻž āĻ•āĻŋ? āĻĒā§ā§°āϤāĻŋāĻŸā§‹ā§° āωāĻĻāĻžāĻšā§°āĻŖ āĻĻāĻŋāϝāĻŧāĻžāĨ¤


Ans / āωāĻ¤ā§āϤ⧰: Solid - Stone, Liquid - Water, Gas - Air. āĻ ā§‹āϏ - āĻĒāĻžāĻĨā§°, āĻĻā§ā§°ā§ą - āĻĒāĻžāύ⧀, āϗ⧇āĻ› - āĻŦāĻžāϝāĻŧ⧁


3) List three characteristics of matter. āĻĒāĻĻāĻžā§°ā§āĻĨā§° āϤāĻŋāύāĻŋāϟāĻž āĻŦ⧈āĻļāĻŋāĻˇā§āĻŸā§āϝ āϞāĻŋāĻ–āĻžāĨ¤


Ans / āωāĻ¤ā§āϤ⧰:



  1. Matter is made of tiny particles. āĻĒāĻĻāĻžā§°ā§āĻĨ āϏ⧰⧁ āϏ⧰⧁ āĻ•āĻŖāĻžā§°ā§‡ āĻ—āĻ āĻŋāϤāĨ¤

  2.  Particles are in constant motion. āĻ•āĻŖāĻžāĻŦā§‹ā§° āϏāĻĻāĻžāϝāĻŧ āϚāϞāĻžāϚāϞ āϕ⧰āĻŋ āĻĨāĻžāϕ⧇āĨ¤

  3. Particles attract each other. āĻ•āĻŖāĻžāĻŦā§‹ā§° āĻĒā§°āĻ¸ā§āĻĒā§°ā§° āĻĒā§°āĻž āφāĻ•ā§°ā§āώāĻŖ āĻ…āύ⧁āĻ­ā§ą āϕ⧰⧇āĨ¤


4) Why is air considered matter ? āĻŦāĻžāϝāĻŧ⧁āĻ• āĻĒāĻĻāĻžā§°ā§āĻĨ āĻ•āĻŋāϝāĻŧ āϧ⧰āĻž āĻšāϝāĻŧ ? 


Ans / āωāĻ¤ā§āϤ⧰: Air has mass and occupies space. āĻŦāĻžāϝāĻŧ⧁⧰ āĻ­ā§° āφāϛ⧇ āφ⧰⧁ āχ āĻ¸ā§āĻĨāĻžāύ āĻĻāĻ–āϞ āϕ⧰⧇āĨ¤


5) What happens to the motion of particles when matter is heated ? āĻĒāĻĻāĻžā§°ā§āĻĨ āĻ—ā§°āĻŽ āϕ⧰āĻŋāϞ⧇ āĻ•āĻŖāĻžā§° āĻ—āϤāĻŋāϤ āĻ•āĻŋ āĻšāϝāĻŧ ?


Ans / āωāĻ¤ā§āϤ⧰: The particles move faster when heated. āĻ—ā§°āĻŽ āĻĻāĻŋāϞ⧇ āĻ•āĻŖāĻžāĻŦā§‹ā§° āĻŦ⧇āĻ›āĻŋ āĻĻā§ā§°ā§āϤ āĻ—āϤāĻŋāϤ āĻ—āϤāĻŋ āϕ⧰⧇āĨ¤


6) Distinguish between solid, liquid, and gas. āĻ•āĻ āĻŋāύ, āĻĻā§ā§°ā§ą āφ⧰⧁ āϗ⧇āϛ⧰ āĻŽāĻžāϜāϤ āĻĒāĻžā§°ā§āĻĨāĻ•ā§āϝ āĻĻāĻŋāϝāĻŧāĻžāĨ¤


Ans / āωāĻ¤ā§āϤ⧰:



  1. Solid: Fixed shape and volume. Example: Stone / Ice āĻ•āĻ āĻŋāύ: āύāĻŋā§°ā§āĻĻāĻŋāĻˇā§āϟ āφāĻ•āĻžā§° āφ⧰⧁ āφāϝāĻŧāϤāύāĨ¤ āωāĻĻāĻžāĻšā§°āĻŖ: āĻĒāĻžāĻĨā§° / āĻŦā§°āĻĢ

  2. Liquid: No fixed shape but fixed volume. Example: Water / Milk āĻĻā§ā§°ā§ą: āύāĻŋā§°ā§āĻĻāĻŋāĻˇā§āϟ āφāĻ•āĻžā§° āύāĻžāĻĨāĻžāϕ⧇, āĻ•āĻŋāĻ¨ā§āϤ⧁ āφāϝāĻŧāϤāύ āύāĻŋā§°ā§āĻĻāĻŋāĻˇā§āϟāĨ¤ āωāĻĻāĻžāĻšā§°āĻŖ: āĻĒāĻžāύ⧀ / āĻĻ⧁āϧ

  3. Gas: No fixed shape or volume. Example: Air / Oxygen āϗ⧇āĻ›: āύāĻŋā§°ā§āĻĻāĻŋāĻˇā§āϟ āφāĻ•āĻžā§° āφ⧰⧁ āφāϝāĻŧāϤāύ āύāĻžāĻĨāĻžāϕ⧇āĨ¤ āωāĻĻāĻžāĻšā§°āĻŖ: āĻŦāĻžāϝāĻŧ⧁ / āĻ…āĻ•ā§āϏāĻŋāĻœā§‡āύ


7) What is meant by the attraction force between particles ? Give an example. āĻ•āĻŖāĻžā§° āĻŽāĻžāϜāϤ āφāĻ•ā§°ā§āώāĻŖ āĻļāĻ•ā§āϤāĻŋ āĻŽāĻžāύ⧇ āĻ•āĻŋ? āωāĻĻāĻžāĻšā§°āĻŖ āĻĻāĻŋāϝāĻŧāĻžāĨ¤


Ans / āωāĻ¤ā§āϤ⧰: Attraction force is the force that holds particles together. Example: Water droplets forming. āφāĻ•ā§°ā§āώāĻŖ āĻļāĻ•ā§āϤāĻŋ āĻŽāĻžāύ⧇ āĻ•āĻŖāĻžāĻŦā§‹ā§° āĻāϕ⧇āϞāϗ⧇ ā§°āĻžāĻ–āĻŋāĻŦāϞ⧈ āĻĨāĻ•āĻž āĻļāĻ•ā§āϤāĻŋāĨ¤ āωāĻĻāĻžāĻšā§°āĻŖ: āĻĒāĻžāύ⧀⧰ āĻĢā§‹āρāϟāĻž āĻŽāĻŋāϞāĻŋ āĻ¯ā§‹ā§ąāĻžāĨ¤


What is Matter ? :: āĻĒāĻĻāĻžā§°ā§āĻĨ āĻ•āĻŋ ? : Click Here


8) Explain why ice has a fixed shape but water does not. āĻŦ⧁āĻœā§‹ā§ąāĻž āĻ•āĻŋāϝāĻŧ āĻŦā§°āĻĢā§° āύāĻŋā§°ā§āĻĻāĻŋāĻˇā§āϟ āφāĻ•āĻžā§° āĻĨāĻžāϕ⧇ āĻ•āĻŋāĻ¨ā§āϤ⧁ āĻĒāĻžāύ⧀⧰ āύāĻžāχāĨ¤


Ans / āωāĻ¤ā§āϤ⧰: In ice, particles are tightly packed - fixed shape. In water, particles can move - no fixed shape. āĻŦā§°āĻĢāϤ āĻ•āĻŖāĻžāĻŦā§‹ā§° āĻļāĻ•ā§āϤāĻ­āĻžāĻŦ⧇ āĻŽāĻŋāϞāĻŋ āφāϛ⧇ - āύāĻŋā§°ā§āĻĻāĻŋāĻˇā§āϟ āφāĻ•āĻžā§°āĨ¤ āĻĒāĻžāύ⧀āϤ āĻ•āĻŖāĻžāĻŦā§‹ā§° āϚāϞāĻŋāĻŦ āĻĒāĻžā§°ā§‡ - āύāĻŋā§°ā§āĻĻāĻŋāĻˇā§āϟ āφāĻ•āĻžā§° āύāĻžāχāĨ¤


9) Draw a labeled diagram showing the three states of matter.āĻĒāĻĻāĻžā§°ā§āĻĨā§° āϤāĻŋāύāĻŋāϟāĻž āĻ…ā§ąāĻ¸ā§āĻĨāĻžā§° āϞ⧇āĻŦ⧇āϞāϏāĻš āĻ›āĻŦāĻŋ āφāρāĻ•āĻžāĨ¤


Ans / āωāĻ¤ā§āϤ⧰: Solid - Ice / Stone , Liquid - Water / Milk , Gas - Air / Oxygen


10) Classify the following as solid, liquid, or gas: Sugar, Milk, Oxygen. āĻāχāĻŦā§‹ā§°āĻ• āĻ•āĻ āĻŋāύ, āĻĻā§ā§°ā§ą āĻŦāĻž āϗ⧇āĻ›āϤ āĻ­āĻžāĻ— āϕ⧰āĻž: āĻšā§‡āύ⧀, āĻĻ⧁āϧ, āĻ…āĻ•ā§āϏāĻŋāĻœā§‡āύ


Ans / āωāĻ¤ā§āϤ⧰: 1. Sugar - Solid / āĻšā§‡āύ⧀ - āĻ—ā§‹āϟāĻž , 2. Milk - Liquid / āĻĻ⧁āϧ - āĻĻā§ā§°ā§ą , 3. Oxygen - Gas / āĻ…āĻ•ā§āϏāĻŋāĻœā§‡āύ - āϗ⧇āĻ›


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1. āϤāϞāϤ āĻĻāĻŋ⧟āĻž āωāĻˇā§āĻŖāϤāĻžāĻŦā§‹ā§° āĻšā§‡āϞāĻ›āĻŋ⧟āĻžāĻ› āĻ¸ā§āϕ⧇āϞāϤ āĻĒā§ā§°āĻ•āĻžāĻļ āϕ⧰āĻžāĨ¤ (Convert the following temperatures into Celsius scale.)


āϏ⧂āĻ¤ā§āϰ / Formula: °C = K − 273


(a) 300 K


āωāĻ¤ā§āϤ⧰ / Ans: 300 − 273 = 27°C, 300 K = 27°C


(b) 573 K


āωāĻ¤ā§āϤ⧰ / Ans: 573 − 273 = 300°C, 573 K = 300°C


2. āϤāϞ⧰ āωāĻˇā§āĻŖāϤāĻžāĻŦāĻŋāϞāĻžāĻ•āϤ āĻĒāĻžāύ⧀⧰ āϭ⧌āϤāĻŋāĻ• āĻ…ā§ąāĻ¸ā§āĻĨāĻž āĻ•āĻŋ āĻšāĻŦ ? (What will be the physical state of water at the following temperatures ?)


(a) 250°C


āωāĻ¤ā§āϤ⧰ / Ans: 250°C āϤ āĻĒāĻžāύ⧀ āϗ⧇āĻ›ā§€ā§Ÿ āĻ…ā§ąāĻ¸ā§āĻĨāĻžāϤ āĻĨāĻžāĻ•āĻŋāĻŦāĨ¤ (At 250°C, water will be in gaseous state.)


(b) 100°C


āωāĻ¤ā§āϤ⧰ / Ans: 100°C āϤ āĻĒāĻžāύ⧀ āωāϤāϞāύ āĻ…ā§ąāĻ¸ā§āĻĨāĻžāϤ āĻĨāĻžāĻ•āĻŋāĻŦ āφ⧰⧁ āϜ⧁āĻ˛ā§€ā§ŸāĻž āφ⧰⧁ āϗ⧇āĻ›ā§€ā§Ÿ āĻĻā§ā§Ÿā§‹ āĻ…ā§ąāĻ¸ā§āĻĨāĻž āĻĨāĻžāĻ•āĻŋāĻŦ āĻĒāĻžā§°ā§‡āĨ¤ (At 100°C, water will be at boiling point and both liquid and gaseous states may exist.)


3. āϕ⧋āύ⧋ āĻĒāĻĻāĻžā§°ā§āĻĨā§° āϭ⧌āϤāĻŋāĻ• āĻ…ā§ąāĻ¸ā§āĻĨāĻžā§° āĻĒā§°āĻŋāĻŦā§°ā§āϤāύ⧰ āϏāĻŽā§ŸāĻšā§‹ā§ąāĻžāϤ āωāĻˇā§āĻŖāϤāĻž āĻ¸ā§āĻĨāĻŋā§° āĻšā§ˆ āĻĨāĻžāϕ⧇ āĻ•āĻŋ⧟ ? (Why does temperature remain constant during the change of state of a substance ?)


āωāĻ¤ā§āϤ⧰ / Ans: āĻ…ā§ąāĻ¸ā§āĻĨāĻžā§° āĻĒā§°āĻŋāĻŦā§°ā§āϤāύ⧰ āϏāĻŽā§ŸāϤ āĻĒā§ā§°ā§Ÿā§‹āĻ— āϕ⧰āĻž āϤāĻžāĻĒ āĻ•āĻŖāĻŋāĻ•āĻžāĻŦā§‹ā§°ā§° āĻŽāĻžāϜ⧰ āφāĻ•āĻ°ā§āώāĻŖ āĻŦāϞ āĻ­āĻžāĻ™āĻŋāĻŦāϞ⧈ āĻŦā§āĻ¯ā§ąāĻšā§ƒāϤ āĻšā§ŸāĨ¤ āϏ⧇āχāĻ•āĻžā§°āϪ⧇ āωāĻˇā§āĻŖāϤāĻž āĻ¸ā§āĻĨāĻŋā§° āĻĨāĻžāϕ⧇āĨ¤ (During change of state, the supplied heat is used to overcome the force of attraction between particles. Therefore, the temperature remains constant.)


4. āĻŦāĻžāϝāĻŧ⧁āĻŽāĻŖā§āĻĄāĻ˛ā§€ā§Ÿ āϗ⧇āĻ› āϜ⧁āĻ˛ā§€ā§ŸāĻž āϕ⧰āĻŋāĻŦ āĻĒā§°āĻž āĻĒāĻĻā§āϧāϤāĻŋ āĻāϟāĻž āĻ•ā§‹ā§ąāĻžāĨ¤ (Name one method by which atmospheric gases can be liquefied.)


āωāĻ¤ā§āϤ⧰ / Ans: āωāĻšā§āϚ āϚāĻžāĻĒ āĻĒā§āĻ°ā§Ÿā§‹āĻ— āϕ⧰āĻŋ āφ⧰⧁ āωāĻˇā§āĻŖāϤāĻž āĻ•āĻŽāĻžāχ āĻŦāĻžāϝāĻŧ⧁āĻŽāĻŖā§āĻĄāĻ˛ā§€ā§Ÿ āϗ⧇āĻ› āϜ⧁āĻ˛ā§€ā§ŸāĻž āϕ⧰āĻŋāĻŦ āĻĒāĻžā§°āĻŋāĨ¤ (Atmospheric gases can be liquefied by applying high pressure and lowering temperature.)


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Evaporation (āĻŦāĻžāĻˇā§āĻĒā§€āĻ­āĻŦāύ) : Clisk Here


Definition: Evaporation is the process by which a liquid changes into vapour from its surface at any temperature below its boiling point. āϏāĻ‚āĻœā§āĻžāĻž: āϜ⧁āĻ˛ā§€ā§ŸāĻž āĻĒāĻĻāĻžā§°ā§āĻĨā§° āĻĒ⧃āĻˇā§āĻ ā§° āĻĒā§°āĻž āωāϤāϞāĻžāĻ‚āϕ⧰ āϤāϞ⧰ āϝāĻŋāϕ⧋āύ⧋ āωāĻˇā§āĻŖāϤāĻžāϤ āϗ⧇āĻ›ā§€ā§Ÿ āĻ…ā§ąāĻ¸ā§āĻĨāĻžāϞ⧈ āĻĒā§°āĻŋāĻŦāĻ°ā§āϤāĻŋāϤ āĻšā§‹ā§ąāĻžāĻ• āĻŦāĻžāĻˇā§āĻĒā§€āĻ­āĻŦāύ āĻŦā§‹āϞ⧇āĨ¤


1. Desert cooler āĻāϟāĻžāχ āĻļ⧁āĻˇā§āĻ• āĻ—ā§°āĻŽ āĻĻāĻŋāύāϤ āĻ­āĻžāϞāĻ•ā§ˆ āĻ āĻžāĻŖā§āĻĄāĻž āϕ⧰⧇ āĻ•āĻŋ⧟ ? (Why does a desert cooler cool better on a hot dry day ?)


āωāĻ¤ā§āϤ⧰ / Ans: āĻļ⧁āĻˇā§āĻ• āĻ—ā§°āĻŽ āĻĻāĻŋāύāϤ āĻŦāĻžāϝāĻŧ⧁āϤ āφāĻ°ā§āĻĻā§āϰāϤāĻž āĻ•āĻŽ āĻĨāĻžāϕ⧇āĨ¤ āĻ¸ā§‡ā§Ÿā§‡ āĻĒāĻžāύ⧀ āĻĻā§āϰ⧁āϤ āĻŦāĻžāĻˇā§āĻĒā§€āĻ­ā§‚āϤ āĻšā§ŸāĨ¤ āĻŦāĻžāĻˇā§āĻĒā§€āĻ­āĻŦāύ⧰ āϏāĻŽā§ŸāϤ āĻĒāĻžāĻ¨ā§€ā§Ÿā§‡ āϚāĻžā§°āĻŋāĻ“āĻĢāĻžāϞ⧰ āĻĒā§°āĻž āĻ…āϧāĻŋāĻ• āϤāĻžāĻĒ āĻļā§‹āώāĻŖ āϕ⧰⧇āĨ¤ āĻĢāϞāϤ desert cooler āĻ āĻŦ⧇āĻ›āĻŋ āĻ āĻžāĻŖā§āĻĄāĻž āϕ⧰⧇āĨ¤ On a hot dry day, humidity in the air is low. So water evaporates faster. During evaporation, water absorbs more heat from the surroundings. Therefore, the desert cooler cools better.


2. āĻ—ā§āϰ⧀āĻˇā§āĻŽāĻ•āĻžāϞāϤ āĻŽāĻžāϟāĻŋā§° āĻ•āϞāĻšā§° āĻĒāĻžāύ⧀ āĻ āĻžāĻŖā§āĻĄāĻž āĻšā§ˆ āĻĨāĻžāϕ⧇ āĻ•āĻŋ⧟ ? (Why does water remain cool in an earthen pot during summer ?)


āωāĻ¤ā§āϤ⧰ / Ans: āĻŽāĻžāϟāĻŋā§° āĻ•āϞāĻšāϤ āϏ⧰⧁ āϏ⧰⧁ ā§°āĻ¨ā§āĻ§ā§ā§° āĻĨāĻžāϕ⧇āĨ¤ āĻāχ ā§°āĻ¨ā§āĻ§ā§ā§°ā§° āĻŽāĻžāĻœā§‡ā§°ā§‡ āĻĒāĻžāύ⧀ āĻŦāĻžāĻšāĻŋā§°āϞ⧈ āφāĻšāĻŋ āĻŦāĻžāĻˇā§āĻĒā§€āĻ­ā§‚āϤ āĻšā§ŸāĨ¤ āĻŦāĻžāĻˇā§āĻĒā§€āĻ­āĻŦāύ⧰ āϏāĻŽā§ŸāϤ āϤāĻžāĻĒ āĻļā§‹āώāĻŖ āϕ⧰āĻžā§° āĻŦāĻžāĻŦ⧇ āĻĒāĻžāύ⧀ āĻ āĻžāĻŖā§āĻĄāĻž āĻšā§ˆ āĻĨāĻžāϕ⧇āĨ¤ An earthen pot has tiny pores. Water comes out through these pores and evaporates. During evaporation, heat is absorbed, so the water remains cool.


3. āĻšāĻžāϤ⧰ āϤāĻ˛ā§ā§ąāĻžāϤ āĻāϚāĻŋāϟāύ, āĻĒ⧇āĻŸā§āϰāϞ āĻŦāĻž āϏ⧁āĻ—āĻ¨ā§āϧāĻŋ āφāϤ⧰ āĻĸāĻžāϞāĻŋ āϞ'āϞ⧇ āĻ āĻžāĻŖā§āĻĄāĻž āĻ…āύ⧁āĻ­ā§ą āĻšā§Ÿ āĻ•āĻŋ⧟ ? Why do we feel cool when acetone, petrol, or perfume is poured on the palm ?


āωāĻ¤ā§āϤ⧰ / Ans: āĻāϚāĻŋāϟāύ, āĻĒ⧇āĻŸā§āϰāϞ āφ⧰⧁ āφāϤ⧰ āĻĻā§āϰ⧁āϤ āĻŦāĻžāĻˇā§āĻĒā§€āĻ­ā§‚āϤ āĻšā§ŸāĨ¤ āĻŦāĻžāĻˇā§āĻĒā§€āĻ­āĻŦāύ⧰ āϏāĻŽā§ŸāϤ āχāĻšāρāϤ⧇ āĻšāĻžāϤ⧰ āϤāĻ˛ā§ā§ąāĻžā§° āĻĒā§°āĻž āϤāĻžāĻĒ āĻļā§‹āώāĻŖ āϕ⧰⧇āĨ¤ āĻ¸ā§‡ā§Ÿā§‡ āĻ āĻžāĻŖā§āĻĄāĻž āĻ…āύ⧁āĻ­ā§ą āĻšā§ŸāĨ¤ Acetone, petrol, and perfume evaporate quickly. During evaporation, they absorb heat from the palm. Therefore, we feel cool.


4. āĻ—ā§°āĻŽ āϚāĻžāĻš āĻŦāĻž āĻ—āĻžāϖ⧀⧰ āĻ•āĻžāĻĒāϤ āϞ⧈ āĻ–ā§‹ā§ąāĻžāϤāĻ•ā§ˆ āĻĒā§āϞ⧇āϟāϤ āϞ⧈ āĻ–ā§‹ā§ąāĻž āϏāĻšāϜ āĻ•āĻŋ⧟ ? Why is it easier to drink hot tea or milk from a plate than from a cup ?


āωāĻ¤ā§āϤ⧰ / Answer: āĻĒā§āϞ⧇āϟāϤ āϚāĻžāĻš āĻŦāĻž āĻ—āĻžāϖ⧀⧰⧰ āĻĒ⧃āĻˇā§āĻ āĻ•āĻžāϞāĻŋ āĻŦ⧇āĻ›āĻŋ āĻšā§ŸāĨ¤ āĻ¸ā§‡ā§Ÿā§‡ āĻŦāĻžāĻˇā§āĻĒā§€āĻ­āĻŦāύ āĻĻā§āϰ⧁āϤ āĻšā§Ÿ āφ⧰⧁ āϤāĻžāĻĒ āϏ⧋āύāĻ•āĻžāϞ⧇ āĻ•āĻŽā§‡āĨ¤ āϏ⧇āχāĻ•āĻžā§°āϪ⧇ āĻĒā§āϞ⧇āϟāϤ āϞ⧈ āĻ–ā§‹ā§ąāĻž āϏāĻšāϜāĨ¤ In a plate, tea or milk has a larger surface area. So evaporation becomes faster and the temperature decreases quickly. Therefore, it is easier to drink from a plate.


5. āĻ—ā§āϰ⧀āĻˇā§āĻŽāĻ•āĻžāϞāϤ āφāĻŽāĻŋ āĻ•āĻŋ āϧ⧰āĻŖā§° āĻ•āĻžāĻĒā§‹ā§° āĻĒāĻŋāĻ¨ā§āϧāĻŋāĻŦ āϞāĻžāϗ⧇ ? What type of clothes should we wear in summer ?


āωāĻ¤ā§āϤ⧰ / Ans: āĻ—ā§āϰ⧀āĻˇā§āĻŽāĻ•āĻžāϞāϤ āĻĒāĻžāϤāϞ āφ⧰⧁ āĻ•āĻĒāĻžāĻšā§€ āĻ•āĻžāĻĒā§‹ā§° āĻĒāĻŋāĻ¨ā§āϧāĻŋāĻŦ āϞāĻžāϗ⧇āĨ¤ āĻ•āĻĒāĻžāĻšā§€ āĻ•āĻžāĻĒ⧋⧰⧇ āϘāĻžāĻŽ āĻļā§‹āώāĻŖ āϕ⧰āĻŋ āϏāĻšāĻœā§‡ āĻŦāĻžāĻˇā§āĻĒā§€āĻ­ā§‚āϤ āĻšā§‹ā§ąāĻžāϤ āϏāĻšāĻžā§Ÿ āϕ⧰⧇ āφ⧰⧁ āĻĻ⧇āĻš āĻ āĻžāĻŖā§āĻĄāĻž ā§°āĻžāϖ⧇āĨ¤ In summer, we should wear light cotton clothes. Cotton absorbs sweat and helps it evaporate easily, keeping the body cool.