AP 9th Class Physical Science Chapter 1 Solution – Matter Around Us
Andhra Pradesh SCERT 9th Class Physical Science Chapter 1 Matter Around Us Solution for AP 9th Class Physics/Chemistry Exam. Lots of Students of Andhra Pradesh Board will search on internet for Andhra Pradesh Class 9 Physical Science Textbook Solution or Study Material for AP 9th exam. Here you search will end! Here in this page we have provided for all question answer for AP SCERT Chapter 1 Matter Around Us.
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AP 9th Class Physics Chapter 1 Matter Around Us Solution
1.) Describe an activity which provides the evidence for (A,S1)
a) the motion of particles
b) attraction between particles
c) inter-particle space
Ans: – a) If we light a incense stick in a room the scent from it moves around the room air. This vapour of scent after some time mixed with the air particle present in the air, this phenomenon of spreading of scent proves the motion of the particle.
b) The force of attraction between the solid particles are stronger than liquid and gases particle. As a result of that we see the mobility of gases particle is more than liquid and solid. Liquid has also weaker force of attraction between them.
c) After mixing the sugar with water we see that there is no change in volume in the bekar. As there are inter particle space in water and the sugar particle occupy this spaces.
2.) Name the characteristics of matter that are demonstrated by diffusion. (A,S1)
Ans: –From the diffusion of matter the characteristics shows about a particle that there is a space between them in a particle and it can move in air.
3.”When sugar is dissolved in water there is no increase in volume”. Is it true or false? Comment on the statement keeping in mind the amount of sugar, amount of etc. (A,S1)
Ans: –When sugar dissolved in water there is no increase in volume it is a true statement.
As there are present inter particle space between the water molecules the sugar present in water occupy the space so we don’t the increase in volume.
4.) Is there any change in mass when a substance changes its state? Explain withexample. (A,S1)
Ans: –From the principle of conservation of mass we know that mass is neither created nor destroyed so mass doesn’t change. For example if wee put 200gm of ice in bekar after some time when it will melt we see that the mass remain 200gm.
5.) Do all substances change from solid to liquid and liquid to gas on heating? Explain. (A,S1)
Ans: –No all substance doesn’t change its state. Naphthalene ball don’t convert to liquid as its dissociation energy is law. But dry ice or solid CO2 convert to gases because of heat.
6.) Define the following terms: (A,S1)
a) melting point b) boiling point c) evaporation
Ans: –a) melting point of a matter is in which temperature it change its state from solid to liquid state.
b) Boiling point of a particle means when any matterstarts to boil in air pressure.
c) when liquid states of any matter changes to gases state,this phenomenon is known as evaporation.
7.) Correct the following statements. (A,S1)
a) Water boils at 100℃ under atmospheric pressure.
b) a liquid evaporates above its boiling point
c) solids have the largest inter-particle space.
d) gases have the strongest inter-particle forces.
Ans: –a) Water boils at 100℃ in the atmosphere and the pressure present in air is known atmospheric pressure.
b) A liquid evaporates above its boiling point this statement is false as we all know that liquid always evaporate bellow its boiling point.
c) As solid has fixed shape and size there must be low inter particle space in solid.
d) As gases have weakest inter particle space they don’t have any fixed shape.
8.) Why do we prefer to sip hot tea with a saucer rather than a cup? (A,S1)
Ans:- We prefer to sip hot tea with a saucer rather than a cup a in a saucer there are more wide area as comparing to cup so evaporation will be more in it.
9.) When water solidifies to ice then heat is (A,S1)
a) Liberated
b) Absorbed
c) No change
d) Depending on the condition of heat absorbed or liberated.
Ans: –When water solidifies it liberated temperature. After some time when water temperature came to under 0℃ it become solid.
10.) Convert the following temperatures to the Celsius scale. (A,S1)
(a) 283k (b) 570k
Ans: – As we know that temperature in Kelvin scale is equal to the sum of 273 + temperature in Celsius scale.
a) 283 k or (283 –273 = 10) 10℃.
b) 570k or (570 – 273= 293) 293℃.
11) Convert the following temperatures to the Kelvin scale. (A,S1)
(a) 270℃(b) 367℃
Ans: –a) 270℃ to Kelvin scale is 270 + 273 = 543 k.
b) 367℃ to Kelvin scale is 367 + 273 = 640 k.
12) How can we smell perfume sitting several metres away from the source? (A,S2)
Ans: –When the perfume liberate from the bottle it changes its state liquid to vapour form. As in the vapour particle there are less force of attraction in them so diffusion is more. That ‘sway smell of perfume felt away from the source.
13.) Steam produces more severe burns than boiling water. Think why? (A,S2)
Ans: – Theboiling point of any particle doesn’t change simultaneously it convert to a liquid to steam by absorbing the energy. As a result of that the temperature of steam is more.
14.) Fill in the blanks. (A,S1)
a) Temperature does not change while a solid substance is …….melting………………… or a liquidsubstance is…boiling….
b) A vapour on cooling changes into …..liquid…………….and on further cooling changesinto……………..solid………………………………..
c) Matter changes from one state to another either raising the ……….. temperature…………………….or lowering the……… pressure…………………….………
d) A change in which a solid on heating directly changes into vapour state is called……… Sublimation………….….
e) The inter particle spaces are…….highest………….…..in gaseous and………..lowest………….…..in solids.
15.) Match the following.(A,S1)
a) conversion of liquid into gas (iv ) (i) gas
b) Non- compressible (ii)(ii) solid
c) maximum expansion (i). (iii) particle
d) constituents of matter (iii). (iv) evaporation
16). How do you appreciate sweating mechanism of human body to control the temperatureof the body? (A,S6)
Ans: – By sweating human body control its temperature of the body. When outside temperature is more than the internal temperature of our body we sweat. As above 98.6F temperature body start to sweat and it evaporate. But humid condition there are more water in air so then so much evaporation of heat would no happened.
17.) Make a model to explain the structure of particles in solids, liquids and gases. (A,S5)
Ans:-
