Q.1
What is matter?
Ans:
Anything which has mass/weight and occupies space is called matter. Everything around us is made up of matter.
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Q.2
What are states of matter?
Ans:
Matter can exist as a
Solid, a
Liquid or a
Gas. These three forms of matter are called the '
States of Matter'. For example water (liquid) can exist as ice (solid) or water vapors (gas).
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Q.3
Write the properties of three (03) states of matter?
Ans:
Everything around us is made up of matter. Matter can exist in three (03) different states. Below is the properties of these three (03) states of matter.
Solid:
Solids have fixed shape, fixed volume and cannot be compressed.
Liquid:
Liquids have not fixed shape but fixed volume and cannot be compressed.
Gas:
Gas have not fixed shape, not fixed volume and can be compressed.
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Q.4
Below is the list of four substances at 20 C
1) Mercury
2) Oil
3) Water Vapour
4) Common Salt
a)-
Which of the sudstances does not have fixed shape and volume, and can be compressed?
Ans:
Water vapour does not have fixed shape and volume, and can be compressed.
b)-
Which of the sudstances contains the most orderly arrangement of particles?
Ans:
Common salt contains the most orderly arrangement of particles
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Q.5
a)-
In which state of matter can the particles move most freely?
Ans:
In state of gas the particles can move most freely.
b)-
In which state of matter are the particles closest together?
Ans:
In state of solid the particles are closest together.
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Q.6
Using the kinetic particle theory,
a)-
Explain why liquids have fixed volumes but not fixed shapes.
Ans:
Liquid have fixed volumes but not fixed shapes because liquid particles are arranged disorderly and are less closely packed together.
b)-
Explain why ice has a higher density than water vapour.
Ans:
Ice has a higher density than water vapour because the particles of solid are arranged orderly and are closely packed together.
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Q.7
What is melting?
Ans:
When a substance changes from a solid to liquid, we say that it is melting.
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What is melting point?
Ans:
The temperature at which a solid becomes a liquid is called its
melting point.
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Q.9
What is freezing?
Ans:
When a substance changes from a liquid to a solid, we say that it is
freezing.
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Q.10
What is freezing point?
Ans:
The temperature at which a liquid becomes a solid is called its
freezing point. Heat energy is given out during the cooling process.
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