(a) Tabulate the differences in the characterisitcs of states of matter.
(b) Comment upon the following: rigidity, compressibility, fluidity, filling a gas container, shape, kinetic energy and density.
(a) Solid:
* Particles are rigid and un-incompressible.
* Particles possess a definite shape and volume.
* Particles don't have the ability to flow.
* Particles have the least kinetic energy.
* Particles have high density. eg.: salt, iron, gold, chalk.
Liquid:
* Particles are not rigid but can be compressed to a limited extent.
* Particles have only a definite volume but acquire the shape of a container in which they are kept.
* Particles can easily flow from higher to the lower level.
* Particles have more kinetic energy than solid.
* Particles have less density than solids. eg.: water, alcohol, petrol etc.
Gas:
* Particles are not rigid and can be compressed easily.
* Particles don't have a definite shape of volume.
* Particles can flow in all the possible directions.
* Particles have maximum kinetic energy.
* Particles have the least density. eg.: air, CNG, smoke etc.
(b)
* Rigidity: It is the property of matter to maintain its shape even if an external force is applied and the solids show it this property.
* Compressibility: It is the property of matter to allow decrease in volume under high pressure and gases show this property.
* Fluidity: It is the property of a substance to easily flow and allow change in its shape under external forces and this property is shown by both liquids and gases.
* Filling a gas container: Gases can be compressed easily hence they can be filled within a vessel at high pressure. This property of gases allows their convenient filling into a small container or cylinder and that also in a large volume. It also allows their easy transport from one place to other e.g. CNG.
* Shape: According to the type of matter shape differ depending upon the location of particles like solid have a definite shape while liquid acquire the shape of their container and gases as such don't have any shape.
* Kinetic energy: It is the kind of energy present in an object when it is under motion as the particles of that object are continuously moving therefore the object has kinetic energy. However, greater is the movement, more will be the kinetic energy and vise-versa.
Kinetic Energy = Gas > Liquid > Solid
Kinetic energy of gas is maximum.
* Density: Mass per unit volume of a substance is known as its density.
Density = Solid > Liquid > Gas
Solids have the greatest density.
Popular Questions of Class 9 Science
- Q:-
Abdul, while driving to school, computes the average speed for his trip to be 20 km h-1. On his return trip along the same route, there is less traffic and the average speed is 40 km h-1. What is the average speed for Abdul’s trip?
- Q:-
An object of mass 40 kg is raised to a height of 5 m above the ground. What is its potential energy? If the object is allowed to fall, find its kinetic energy when it is half-way down.
- Q:-
A driver of a car travelling at 52 km h-1 applies the brakes and accelerates uniformly in the opposite direction. The car stops in 5 s. Another driver going at 3 km h-1 in another car applies his brakes slowly and stops in 10 s. On the same graph paper, plot the speed versus time graphs for the two cars. Which of the two cars travelled farther after the brakes were applied?
- Q:-
Fig 8.11 shows the distance-time graph of three objects A,B and C. Study the graph and answer the following questions:
Fig. 8.11
(a) Which of the three is travelling the fastest?
(b) Are all three ever at the same point on the road?
(c) How far has C travelled when B passes A?
(d) How far has B travelled by the time it passes C? - Q:-
Two objects, each of mass 1.5 kg, are moving in the same straight line but in opposite directions. The velocity of each object is 2.5 m s-1 before the collision during which they stick together. What will be the velocity of the combined object after collision?
- Q:-
Soni says that the acceleration in an object could be zero even when several forces are acting on it. Do you agree with her? Why?
- Q:-
Two objects of masses 100 g and 200 g are moving along the same line and direction with velocities of 2 m s-1 and 1 m s-1, respectively. They collide and after the collision, the first object moves at a velocity of 1.67 m s-1. Determine the velocity of the second object.
- Q:-
How do poriferan animals differ from coelenterate animals?
- Q:-
The speed-time graph for a car is shown is Fig. 8.12.
Fig. 8.12
(a) Find how far does the car travel in the first 4 seconds. Shade the area on the graph that represents the distance travelled by the car during the period.
(b) Which part of the graph represents uniform motion of the car? - Q:-
How are sol, solution and suspension different from each other?
Recently Viewed Questions of Class 9 Science
- Q:-
Why is it difficult to hold a school bag having a strap made of a thin and strong string?
- Q:-
A driver of a car travelling at 52 km h-1 applies the brakes and accelerates uniformly in the opposite direction. The car stops in 5 s. Another driver going at 3 km h-1 in another car applies his brakes slowly and stops in 10 s. On the same graph paper, plot the speed versus time graphs for the two cars. Which of the two cars travelled farther after the brakes were applied?
- Q:-
In the following example, try to identify the number of times the velocity of the ball changes: “A football player kicks a football to another player of his team who kicks the football towards the goal. The goalkeeper of the opposite team collects the football and kicks it towards a player of his own team”.
Also identify the agent supplying the force in each case. - Q:-
What are the functions of the stomata?
- Q:-
List any three human activities that you think would lead to air pollution.
- Q:-
Calculate the number of aluminium ions present in 0.051 g of aluminium oxide.
(Hint: The mass of an ion is the same as that of an atom of the same element. Atomic mass of Al = 27 u) - Q:-
Name the regions in which parenchyma tissue is present.
- Q:-
How many times did you fall ill in the last one year? What were the illnesses?
(a) Think of one change you could make in your habits in order to avoid any of/most of the above illnesses.
(b) Think of one change you would wish for in your surroundings in order to avoid any of/most of the above illnesses. - Q:-
Identify the solutions among the following mixtures.
(a) Soil
(b) Sea water
(c) Air
(d) Coal
(e) Soda water. - Q:-
An object of mass 40 kg is raised to a height of 5 m above the ground. What is its potential energy? If the object is allowed to fall, find its kinetic energy when it is half-way down.
- NCERT Chapter