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प्रश्न
State two important uses of following metal:
Uses of gold
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उत्तर
Uses of gold :
- It is used for making jewellery and coins.
- It is used in dentistry for filling cavities in teeth
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संबंधित प्रश्न
Saloni took a piece of burning charcoal and collected the gas evolved in a test tube.
(a) How will she find the nature of the gas?
(b) Write down word equations of all the reactions taking place in this process.
State one use of the following metal:
Aluminium
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.
Aluminium is not used to make :
Name a metal which is best conductor of electricity :
State two important uses of following metal:
Uses of zinc
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:
Sulphuric acid
Write name.
Molecular formula of the common ore of aluminium.
Write scientific reason.
Generally the ionic compounds have high melting points.
Write scientific reason.
Pine oil is used in froth flotation.
Which is the non-ionic compound in the compounds given below.
AgNO3 + Nacl → AgCl + NaNO3
With reference to the following metals state their use in daily life metal:
Zinc
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.
A white crystalline solid which decrepitates on heating leaving a residue which fuses with the glass and evolves two gases one of which is coloured and acidic.
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.
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.
In the following figure, you find that the bulb glows when an iron nail is placed between two ends of wire. Complete the following sentences on the basis of this fact.
- ______ is a metal.
- Metals are good ______ of electricity.
Match the following
| i. | Softest metal | a. | Copper |
| ii. | Hardest metal | b. | Sodium |
| iii. | Hardest non–metal | c. | Osmium |
| iv. | Ductility | d. | Diamond |
Why do metals appear shiny?
