Class 9 Science - Chapter Matter in Our Surroundings NCERT Solutions | Give reasons (a) A gas fills complete
Give reasons
(a) A gas fills completely the vessel in which it is kept.
(b) A gas exerts pressure on the walls of the container.
(c) A wooden table should be called a solid.
(d) We can easily move our hand in air but to do the same through a solid block of wood we need a karate expert.
(a) Since the attraction force between particles of a gas in negligible i.e., that is extremely less hence particles freely move in all possible directions as a result gas fills completely the vessel in which it is kept.
(b) Freely moving particles of gas hit the walls of its container continuously and randomly therefore such random and erratic motion of gas particles exerts pressure on the walls of the container.
(c) A wooden table should be a solid because the particles of wooden table are quite rigid, have a fixed location and also possess a definite shape and volume. Due to all these properties we should call a wooden table a solid substance.
(d) Air is a mixture of gases and since particles of gal are far apart so the name is true for air therefore we can easily move our hand in air. But a solid block of wood is hard and rigid that resists any change in location of its particles hence we need a karate expert in case of a solid block of wood.
More Questions From Class 9 Science - Chapter Matter in Our Surroundings
- Q:-
What type of clothes should we wear in summer?
- Q:-
Name A,B,C,D,E and F in the following diagram showing change in its state
- Q:-
Give two reasons to justify—
(a) water at room temperature is a liquid.
(b) an iron almirah is a solid at room temperature. - Q:-
Suggest a method to liquefy atmospheric gases.
- Q:-
Give reason for the following observations.
(a) Naphthalene balls disappear with time without leaving any solid.
(b) We can get the smell of perfume sitting several metres away. - Q:-
Which of the following are matter?
Chair, air, love, smell, hate, almonds, thought, cold, cold-drink, smell of perfume.
- Q:-
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.
- Q:-
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.
- Q:-
Convert the following temperature to celsius scale:
a. 300 K b. 573 K.
- Q:-
Convert the following temperatures to the Kelvin scale.
(a) 25°C (b) 373°C.
Popular Questions of Class 9 Science
- Q:-
Which of the following has more inertia: (a) a rubber ball and a stone of the same size? (b) a bicycle and a train? (c) a five-rupees coin and a one-rupee coin?
- Q:-
State the universal law of gravitation.
- Q:-
A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (Fig. 11.3). Let us take it that the force acts on the object through the displacement. What is the work done in this case?
- Q:-
What is meant by a pure substance?
- Q:-
How does the sound produced by a vibrating object in a medium reach your ear?
- Q:-
In a reaction, 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium observations are in agreement with the law of conservation of mass.
sodium carbonate + ethanoic acid → sodium ethanoate + carbon dioxide + water
- Q:-
What are canal rays?
- Q:-
State any two conditions essential for good health.
- Q:-
How is our atmosphere different from the atmospheres on Venus and Mars?
- Q:-
Who discovered cells, and how?
Recently Viewed Questions of Class 9 Science
- Q:-
Write down the names of following formulae:
(i) Al2(SO4)3
(ii) CaCl2
(iii) K2SO4
(iv) KNO3
(v) CaCO3. - Q:-
Why is the cell called the structural and functional unit of life?
- Q:-
When 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of carbon dioxide is produced. What mass of carbon dioxide will be formed when 3.00 g of carbon is burnt in 50.00 g of oxygen? Which law of chemical combination will govern your answer?
- Q:-
How does an Amoeba obtain its food?
- Q:-
For the following statements, write T for True and F for False.
(a) J.J. Thomson proposed that the nucleus of an atom contains only nucleons.
(b) A neutron is formed by an electron and a proton combining together. Therefore, it is neutral.
(c) The mass of an electron is about 1/2000 times that of proton.
(d) An isotope of iodine is used for making tincture iodine, which is used as a medicine.Put tick (✓) against correct choice and cross (✕) against wrong choice in questions 15, 16 and 17.
- Q:-
If number of electrons in an atom is 8 and number of protons is also 8, then (i) what is the atomic number of the atom? and (ii) what is the charge on the atom?
- Q:-
Explain how sound is produced by your school bell.
- Q:-
Who discovered cells, and how?
- Q:-
Helium atom has an atomic mass of 4 u and two protons in its nucleus. How many neutrons does it have?
- Q:-
The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes 168 X and 188 X in the sample?
- All Chapters Of Class 9 Science
- All Subjects Of Class 9