Advertisements
Advertisements
प्रश्न
In a beam of sunlight entering a room, we can sometimes see dust particles moving in a haphazard way in the air. Why do these dust particles move?
Advertisements
उत्तर
When a beam of sunlight enters a room, suspended dust particles are seen moving haphazardly. This is because the dust particles are constantly hit by the fast moving particles of air and due to this remain suspended despite gravity acting on them. This is an example of Brownian motion.
APPEARS IN
संबंधित प्रश्न
Define the term matter. What is it composed of?
Liquids have definite volume but do not have definite shape.
Gases have definite volume but no definite shape.
Describe in your own words, what happens to the particles when salt dissolves in water.
Name a liquid which can be classified as a pure substance and conducts electricity.
What is meant by saying that metals are malleable and ductile ?
Explain why, hydrogen and oxygen are considered elements whereas water is not considered an element.
Out of a colloid, solution and a suspension :
which one has the smallest particles ?
Choose one term from the following which includes the other three :
aerosol, emulsion, colloid, sol
Classify the following into solutions, suspensions and colloids :
Soda-water, Milk, Brine, Blood, Ink, Smoke in air, Chalk water mixture, Milk of Magnesia, Shaving cream, Muddy river water.
What will happen if a saturated solution is :
- heated
- cooled
How will you separate a mixture of common salt, sulphur powder and sand ?
Which method is better for recovering sugar from sugar solution : evaporation or crystallisation ? Give reason
for your answer.
How is water purified on a large scale at water works ? Explain with the help of a labelled diagram. Name the substance which is added to kill germs in the drinking water supply ?
Explain how, nitrogen , oxygen and argon gases are separated from air.
Pure copper sulphate can be obtained from an impure sample by the process of :
The material which is added to water during purification process at the water works so as to disinfect it is :
The technique which is used to separate particles of a solid suspended in a liquid quickly is called :
What type of matter glass is?
Define the term matter.
