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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
Fill in the blanks:
Metals react with acids to produce _________ gas.
Which property of graphite is utilised in making electrodes?
How does the electrical conductivity of copper alloys, brass and bronze, differ from that of pure copper?
What is meant by 22 carat gold? Name the metals which are usually alloyed with gold to make it harder.
A metal with melting point less than 50°C is
State two important uses of following metal:
Uses of silver
State the position of the following in the periodic table:
Aluminium
Why are alkali metals kept in kerosene oil?
Write name.
Molecular formula of the common ore of aluminium.
Write scientific reason.
Sodium is always kept in kerosene.
Give a reason why iron objects rust easily but the iron pillar at Qutab Minar has not rusted over the years.
State a specific reason for using copper in electrical cables
On heating which of the following substances i.e. copper carbonate, zinc carbonate, washing soda, copper sulphate, zinc nitrate, copper nitrate, lead nitrate, ammonium chloride and ammonium dichromate – relate to the reaction given below.
An amorphous substance which turns from pale green to black on strong heating evolving a colourless, acidic gas as the only gaseous product.
Why are bells made of metals?
A is a reddish-brown metal, which combines with O2 at < 1370 K gives B, a black coloured compound. At a temperature > 1370 K, A gives C which is red in colour. Find A, B, and C with reaction.
Generally, metals are solid in nature. Which one of the following metals is found in a liquid state at room temperature?
Which of the following property is generally not shown by metals?
The liquid metal at room temperature ______.
Metals and non–metals are used for making ______, ______ and ______.
Silver and copper are very good conductors of electricity.
