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प्रश्न
State two physical properties on the basis of which metals can be distinguished from non-metals.
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उत्तर
| Properties | Metals | Non-metals |
| Lustre | Lustrous | Non-lustrous |
| Heat and electrical conductivity | Good conductor | Poor conductor |
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संबंधित प्रश्न
What are molecules ?
Classify the following into elements, compounds and mixtures:
- Sodium
- Soil
- Sugar solution
- Silver
- Calcium carbonate
- Tin
- Silicon
- Coal
- Air
- Soap
- Methane
- Carbon dioxide
- Blood
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.
Classify the following as elements or compounds :
Iron, Iron sulphide, Sulphur, Chalk, Washing soda, Sodium, Carbon, Urea
What are the three general classes of matter ? Give one example of each type.
“Is malleable and ductile” best describes :
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(a) Which liquid could be an element ? Name this element.
(b) Which liquid could be a mixture ? Name this mixture.
(c) Which liquid could be a compound ? Name this compound.
(d) What could the solid D be ?
(e) What do you think is liquid E ?
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Fill in the following blanks with suitable words :
Immiscible liquids are separated by using a .....................
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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
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(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 is always accompanied by ______ in temperature.
