# Sample questions science class 9

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.  Tabulate the differences in the characteristics of states of matter.

Answer: Difference in the characteristics of 3 states of matter.

 Characteristics Solid Liquid Gas Shape Fixed shape No Fixed shape No Fixed shape Volume Fixed volume Fixed volume No Fixed volume Intermolecular force Maximum Less than solids Very less Intermolecular space Very less More than solids maximum Rigidity/Fluidity Rigid/cannot flow Can flow/not rigid Can flow/not rigid Compressibility negligible compressible Highly compressible

Question 3. Convert the following temperature to Celsius scale:

a. 300K          b. 573K

Solution:

a.  0°C=273K

300K= (300-273)°C = 27°C

b. 573K= (573-273)°C = 300°C

Question 4. What is the physical state of water at:
(a) 250°C (b) 100°C
Answer: (a) 250°C = gas (b) 100°C liquid as well as gas

Question 5. Why does a desert cooler cool better on a hot dry day?
Answer: The outer walls of the cooler get sprinkled by water constantly. This water evaporates due to hot dry weather. Evaporation causes cooling of inside air of cooler. This cool air is sent in the room by the fan.