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प्रश्न
What is an amalgam?
उत्तर
Amalgam is an alloy of mercury with one or more metals. Sodium along with liquid mercury is known as sodium amalgam. Amalgam of mercury with tin, silver and zinc is widely used in dental filling.
संबंधित प्रश्न
Explain how, a reduction reaction of aluminium can be used for welding cracked machine parts of iron. Write a chemical equation for the reaction involved.
For the reduction of metal oxide, suggest a reducing agent other than carbon.
State two important uses of following metal
Uses of copper
Take an element from an alkali metal and one from an alkaline earth metal and write an equation for their action with:
Oxygen
The electronic configuration of metal ‘A’ is 2,8,1 and that of metal ‘B’ is 2,8,2. Which of the two metals is more reactive? Write their reaction with dilute hydrochloric acid.
What was Mendeleev's basis for the classification of elements?
What is it made from? Why?
A pair of tongs.
What is it made from? Why?
Ornaments
With reference to the following metals state their use in daily life metal:
iron
With reference to the following metals state their use in daily life metal:
Magnesium
The minerals from which the metal can be separated economically are called _______.
Soft metal : Na : : hard metal : _______
The metal which is liquid at room temperature is ______.
Higher Order Thinking Skills.
Aakash noticed that the metal latch on gate was difficult to open during hot sunny days. However, it was not difficult to open the same latch at night. Aakash observed that the latch and the gate are exposed to the sun during day time.
- Formulate a hypothesis based on the information provided.
- Briefly state how you would test the hypothesis.
Assertion: Mercury is solid in room temperature.
Reason: Mercury is a non-metal.
An element forms an oxide A2O3 which is acidic in nature. Identify A as a metal or non-metal.
Give an example of a metal which
- is liquid at room temperature.
- is the best conductor of heat.
Match the following
| i. | Softest metal | a. | Copper |
| ii. | Hardest metal | b. | Sodium |
| iii. | Hardest non–metal | c. | Osmium |
| iv. | Ductility | d. | Diamond |
Match the following
| i. | Silica | a. | Caustic potash |
| ii. | Potassium hydroxide | b. | Sand |
| iii. | Sodium hydroxide | c. | Calamine |
| iv. | Zinc carbonate | d. | Caustic soda |
Which metals are not solid at room temperature?
