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प्रश्न
Write scientific reason.
Generally the ionic compounds have high melting points.
उत्तर
- Ionic compounds are composed of cations and anions.
- These ions are held together by strong electrostatic forces of attraction.
- Considerable amount of energy is required to break these strong forces of attraction.
Hence, the melting points of ionic compounds are high.
संबंधित प्रश्न
State one use of Aluminium.
Mention two uses of the following metals and non-metals
Oxygen
Give reasons
Aluminium is used in making aircrafts.
Statements given below are incorrect. Write the correct statements :
Zinc is used for making power transmission wires.
State two important uses of following metals:
Uses of iron
State two important uses of following metal
Uses of tin
Write name.
Molecular formula of the common ore of aluminium.
Write name.
The device used for grinding an ore.
Write scientific reason.
Pine oil is used in froth flotation.
Write scientific reason.
Anodes need to be replaced from time to time during the electrolysis of alumina.
When a copper coin is dipped in silver nitrate solution, a glitter appears on the coin after some time. Why does this happen? Write the chemical equation.
With reference to the following metals state their use in daily life metal:
Aluminium
With reference to the following metals state their use in daily life metal:
Silver
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.
Which one of the following is an example for a metal?
Give reasons for the following.
- Aluminum foils are used to wrap food items.
- Immersion rods for heating liquids are made up of metallic substances.
- Sodium and potassium are stored in kerosene.
- Mercury is used in thermometers.
Which of the following property is generally not shown by metals?
The liquid metal at room temperature ______.
Silver and copper are very good conductors of electricity.
