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प्रश्न
Give reasons
Graphite is used in the leads of pencils
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उत्तर
Graphite turns paper black that is why it is used in the leads of pencils.
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संबंधित प्रश्न
Give reasons for the following.
Copper cannot displace zinc from its salt solution.
State one use of Silver.
Fill in the following blank with suitable word:
The electrical conductivity and melting point of an alloy is ........... than that of pure metals.
Give reasons
Gold is mixed with copper and nickel.
A metal with melting point less than 50°C is
Fill in the blank spaces by choosing the correct words from the given list.
List: amalgam, chlorine, gallium, sodium chloride, silver chloride
Salt of silver, such as ________ is used for making photographic films.
State two important uses of following metal:
Uses of silver
State the position of the following in the periodic table:
Alkali metals
State the position of the following in the periodic table:
Iron and zinc
Take an element from an alkali metal and one from an alkaline earth metal and write an equation for their action with:
Oxygen
Write name.
The oxide that forms salt and water by reacting with both acid and base.
Write scientific reason.
Pine oil is used in froth flotation.
What is it made from? Why?
A pair of tongs.
Name the following:
The chemical compound responsible for the green deposit on the surface of articles of copper.
Why are bells made of metals?
The electronic configurations of three elements X, Y and Z are X – 2, 8; Y – 2, 8, 7 and Z – 2, 8, 2. Which of the following is correct?
Metals are ______ conductors of heat and electricity.
Silver and copper are very good conductors of electricity.
Match the following
| i. | Silica | a. | Caustic potash |
| ii. | Potassium hydroxide | b. | Sand |
| iii. | Sodium hydroxide | c. | Calamine |
| iv. | Zinc carbonate | d. | Caustic soda |
