Class-9 Subject-Science Chapter-1 Slot-1 MATTER IN OUR SURROUNDINGS

 
EVENTS CONVENT HIGH SCHOOL
27/07/2021           CLASS-9             SESSION2021-22(SLOT-1)
SCIENCE
Chapter-1
MATTERS IN OUR SURROUNDING
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Matter in our Surrounding watch full Video.

I.Multiple Choice Questions:-

 Question 1.Which of the following substances is solid?

(a) Plasma

(b) BEC

(c) Wood

(d) Mercury

Answer:

(c) Wood

 

Question 2.Fusion is the phenomenon of changing of state of __________ .

(a) Liquid to gas

(b) Solid to liquid

(c) Solid to gas

(d) Gas to plasma.

Answer:

(b) Solid to liquid

 

Question 3.Diffusion is not possible in the case of __________ .

(a) Liquid into Solid

(b) Gas into liquid

(c) Gas into Gas

(d) Solid into Solid.

Answer:

(d) Solid into Solid.

 

Question 4.Compressibility is highest in __________ .

(a) Liquid

(b) Solid

(c) Gas

(d) Plasma.

Answer:

(c) Gas

 

Question 5.We can smell odour of deodrant several metres away due to __________ .

(a) Diffusion

(b) Evaporation

(c) Fusion

(e) None.

Answer:

(a) Diffusion

 

Question 6.Which of the following do not exhibit sublimation?

(a) Water

(b) Camphor

(c) Naphthalene

(d) Dry ice.

Answer:

(a) Water

 

Question 7.Ice floats on water because of __________ .

(a) Higher density than water

(b) Equal density than water

(c) Lower density than water

(d) None of these.

Answer:

(c) Lower density than water

 

Question 8.As the pressure of air increases then boiling point of liquid __________ .

(a) Increases

(b) Decreases

(c) Remains same

(d) None of these.

Answer:

(a) Increases

 

Question 9.The atmospheric pressure equals to __________ .

(a) 1.01325 × 108 Pa

(b) 101.3 25 × 104 Pa

(c) 1.01325 × 105 Pa

(d) 1.01325 × 102 Pa.

Answer:

(c) 1.01325 × 105 Pa

 

Question 10.Cooking at high altitudes is difficult because __________ .

(a) Boiling point decreases

(b) Boiling point increases

(c) Freezing point reduced

(d) None of the above.

Answer:

(a) Boiling point decreases

 

Question 11.Density of water is highest at __________ .

(a) 3°C

(b) 5°C

(c) 4°C

(d) 6°C.

Answer:

(a) 3°C

 

Question 12.Dry ice is __________ .

(a) Solid carbon monoxide (CO)

(b) Solid Nitrogen dioxide (NO2)

(c) Solid carbon dioxide (CO2)

(d) Solid Ammonia (NH3).

Answer:

(c) Solid carbon dioxide (CO2)

 

 II.ANSWER THE FOLLOWING QUESTIONS:-

Question 1.Which of the following are matter? Chair air, love, smell, hate, almonds, thought, cold, cold – drink smell of perfume.

Answer:Chair, air, almonds and cold – drink.

Question 2.Give reasons for the following observation: The smell of hot sizzling food reaches you several metres away, but to get the smell from cold food you have to go close.

Answer:The particles of hot food have more kinetic energy due to higher temperature, so their rate of diffusion is more and they move several meters away as compared to the particles of cold food.

Question 3.A diver is able to cut through water in a swimming pool. Which property of matter does this observation show?

Answer:This shows that the particles of matter have space between them and a weak force of attraction between them.

 Question 4.What are the characteristics of the particles of matter?

Answer:Following are the characteristics of the particles of matter:

 Particles of matter are very small.

Particles of matter have space between them.

Particles of matter are continuously moving.

Particles of matter attract each other.

 Question 5.The mass per unit volume of a substance is called density, (density = mass / volume). Arrange the following in order of increasing density: air, exhaust from chimneys, honey, water, chalk, cotton and iron.

Answer:The order of increasing densities:

air < exhaust from chimneys < cotton < water < honey < chalk < iron.

 Question 6.Suggest a method to liquefy atmospheric gases.

Answer:The atmospheric gases can be liquefied by cooling and applying pressure on them in a closed chamber or cylinder.

 

Question 7.Why does a desert cooler cool better on a hot dry day?

Answer:On a hot dry day, the rate of evaporation is high because of low humidity. So, water sprinkling on the pads of cooler gets evaporated from outside which results in making its walls cool and then we receive cool air.

 

Question 8.How does the water kept in an earthen pot (matka) become cool during summer?

Answer:The earthen pot has a lot of pores on its surface. So, water comes out and gets evaporated from these pores and cools the water inside the pot.

 

Question 9.Why does our palm feel cold when we put some acetone or petrol or perfume on it?

Answer:When we put acetone, petrol or perfume on our palm, then these liquids absorb energy from our palm and get evaporated which cause cooling effect on our palm.