Matter in our surrounding

S.No	9th , Science, "Matter in our surrounding"
	In text questions page number 3
1.	Which of the following are matter? Chair, air, love, smell, hate, almonds, thought, cold, cold drink, smell of perfume.
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.
3	A diver is able to cut throughwater in a swimming pool. Whichproperty of matter does thisobservation show?
4	What are the characteristics ofthe particles of matter?
	In text questions page number 6
1	The mass per unit volume of asubstance is called density.(density = mass/volume).Arrange the following in order ofincreasing density – air, exhaustfrom chimneys, honey, water,chalk, cotton and iron.
2	(a) Tabulate the differences inthe characteristics of statesof matter.(b) Comment upon the following:rigidity, compressibility,fluidity, filling a gascontainer, shape, kineticenergy and density.
3	Give reasons(a) A gas fills completely thevessel in which it is kept.(b) A gas exerts pressure on thewalls of the container.(c) A wooden table should becalled a solid.(d) We can easily move our handin air but to do the samethrough a solid block of woodwe need a karate expert.
4	Liquids generally have lowerdensity as compared to solids.But you must have observed thatice floats on water. Find out why.
	In text questions page number 9
1	Convert the following temperatureto  Celsius scale:a. 300 K b. 573 K.
2	What is the physical state ofwater at:a. 250ºC b. 100ºC ?
3	For any substance, why does thetemperature remain constantduring the change of state?
4	Suggest a method to liquefyatmospheric gases.
	In text questions page number 10
1	Why does a desert cooler coolbetter on a hot dry day?
2	How does the water kept in anearthen pot (matka) become coolduring summer?
3	Why does our palm feel coldwhen we put some acetone orpetrol or perfume on it?
4	Why are we able to sip hot tea ormilk faster from a saucer ratherthan a cup?
5	What type of clothes should wewear in summer?
	Text Book Exercise
1	Convert the following temperatures to the Celsius scale.(a) 300 K (b) 573 K.
2	Convert the following temperatures to the Kelvin scale.(a) 25°C (b) 373°C.
3	Give reason for the following observations.(a) Naphthalene balls disappear with time without leaving anysolid.(b) We can get the smell of perfume sitting several metres away.
4	Arrange the following substances in increasing order of forcesof attraction between the particles— water, sugar, oxygen.
5	What is the physical state of water at—(a) 25°C (b) 0°C (c) 100°C ?
6	Give two reasons to justify—(a) water at room temperature is a liquid.(b) an iron almirah is a solid at room temperature.
7	Why is ice at 273 K more effective in cooling than water at thesame temperature?
8	What produces more severe burns, boiling water or steam?
9	Name A,B,C,D,E and F in the following diagram showing changein its state