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प्रश्न
Explain the meaning of the term matter with special reference to the term ‘substance’.
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उत्तर
Matter refers to anything that has mass, occupies space, and can be felt by the senses. A substance is a type of matter with a consistent chemical composition and characteristic properties.
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संबंधित प्रश्न
Fill in the following blank with suitable words :
The best evidence that the particles of matter are constantly moving comes from the studies of ................. and ...................
State two characteristics of matter demonstrated by Brownian motion.
When a crystal of potassium permanganate is placed in a beaker, its purple colour spreads throughout the water. What does this observation tell us about the nature of potassium permanganate and water?
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?
The best evidence for the existence and movement of particles in liquids was provided by :
Explain why, osmosis can be considered to be a special kind of diffusion. Classify the following into
(i) osmosis, and (ii) diffusion :
- swelling up of a raisin on keeping in water
- spreading of virus on sneezing
- earthworm dying on coming in contact with common salt
- shrinking of grapes kept in thick sugar syrup
- preserving of pickles in salt
- spreading of smell of cake being baked in the kitchen
- aquatic animals using oxygen dissolved in water during respiration
When extremely small particles X derived from the anther of a flower were suspended in a liquid Y and observed through a microscope, it was found that the particles X were moving throughout the liquid Y in a very zig-zag way. It was also observed that warmer the liquid Y, faster the particles X moved on its surface.
- What could particles X be ?
- What do you think liquid Y is ?
- What is the zig-zag movement of X known as ?
- What is causing the zig-zag movement of particles X ?
- Name the scientist who discovered this phenomenon.
- What does this experiment tell us about the nature of liquid Y?
Fill in the following blanks with suitable words :
The elements which are sonorous are called ..........................
Name two solid, two liquid and two gaseous elements at the room temperature.
Give reason why copper metal is used for making electric wires.
The elements which normally exist in the liquid state are :
In what respects does a true solution differ from a colloidal solution ?
Classify the following into true solutions and colloidal solutions:
Ink, Salt solution, Starch solution, Blood, Sugar solution
Milk of Magnesia is :
When the solid A is added to water, it dissolves with the evolution of a lot of heat and making little explosions to form two products B and C. The properties of products B and C are entirely different from those of solid A as well as water. Moreover, products B and C cannot be reconverted into solid A and water. When another solid D is added to water, it dissolves with the absorption of a little heat to form a product E which cools down. The product E shows the properties of both, solid D as well as water. Moreover, product E can be converted into solid D and water.
(a) What type of change occurs when solid A is dissolved in water ? Why ?
(b) What type of change occurs when solid D is dissolved in water ? Why ?
(c) Name a metal which you think could behave like solid A. Also name the products B and C.
(d) Name the solid D if it is the one which is used in making ordinary dry cells.
(e) Name the process by which D can be recovered from E.
Which of the following cannot be separated from air by the process of fractional distillation ?
The liquid air has three components X, Y and Z whose boiling points are : –186°C, –183°C and –196°C,
respectively. When liquid air is fed into a tall fractional distillation column from near its bottom and warmed
up slowly :
(a) Which component will be collected from near the bottom of the fraction distillation column ? Why ?
(b) Which component will be collected from the top part of the fractional distillation column ? Why ?
(c) Which component will be collected from the middle part of the fractional distillation column ? Why ?
(d) What could the component X, Y and Z be ?
Evaporation does form bubbles.
The phenomenon of Evaporation takes place at the ______ of a liquid.
Define the term matter.
