Advertisements
Advertisements
प्रश्न
An inflated balloon full of air goes down slowly (becomes smaller and smaller slowly) even though the knot at the mouth of the balloon is airtight. And after a week all the air has escaped from the balloon. Explain how the air particles got out of the balloon.
Advertisements
उत्तर
The fast moving molecules of air trapped in the inflated balloon exert continuous pressure on the thin, stretched rubber sheet of balloon and keep on diffusing out through it gradually. Therefore, the air escapes out of the balloon after some time.
APPEARS IN
संबंधित प्रश्न
Liquids have definite volume but do not have definite shape.
Fill in the blank
All matter is made up of tiny particles called ______
Write true or false for each statement. Rewrite the false statement correctly.
Matter cannot exist in different states.
What are pure substances ? Give two examples of pure substances.
Name a metal which can be easily cut with a knife.
“Is malleable and ductile” best describes :
Iron powder and sulphur powder were mixed together and divided into two parts A and B. When part A was heated strongly over a burner, then a substance C was formed. The part B was, however, not heated at all. When dilute hydrochloric acid was added to substance C, then gas D was evolved and when dilute hydrochloric acid was added to part B then gas E was evolved.
- What type of substance is B ?
- What type of substance is C ?
- Name the gas (i) D, and (ii) E ?
- State one characteristic property of gas D.
- Write one test to identify gas E.
What is the most common way of expressing the concentration of a solution ?
State whether the following statement is true or false :
Sponge is an example of solid sol.
Fill in the following blank :
A colloid is a ..............mixture and its components can be separated by the technique known as ...............
Define solvent.
Which of the following represents the solubility of sugar in water at 20°C ?
The solubility of ammonium chloride in water at various temperatures is given below :
| Temperature | : | 10°C | 20°C | 40°C | 60°C | 80°C |
| Solubility | : | 24 g | 37 g | 41 g | 55 g | 66 g |
What mass of ammonium chloride would be needed to make a saturated solution of ammonium chloride in fifty grams of water at 40°C ?
Name the process which can be used to purify an impure sample of copper sulphate.
Fill in the following blanks with suitable words :
The gases of air can be separated by fractional distillation of liquid air because they have different..............
Select the correct answer from A, B, C, D & E for the statement given below:
An atom or group of atoms _________ having a resultant charge.
The physical state of water at 373 K is ______.
Give an example of a molecule.
Write scientific reason.
Lemon sherbat has sweet, sour and salty taste and it can be poured in a glass.
Define the term matter.
