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प्रश्न
How many carats is pure gold? Why is pure gold not suitable for making ornaments?
उत्तर
24-carat gold is pure gold. Pure gold is too soft and it is not possible to make ornaments from this soft gold. Thus, 24-carat gold is mixed with two parts of copper or silver for making jewellery. The gold used for jewellery is 22-carat gold.
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संबंधित प्रश्न
Define the Ore.
Name one ore of copper (other than cuprite). Which compound of copper is present in this ore? Also, write its chemical formula.
Name the gas produced when calamine ore is calcined.
Name two ores of zinc. Write the names of the chemical compounds present in them and give their chemical formulae.
Aluminum is used in thermite welding:
what is thermit?
Define the following term.
Mineral
Correct the following statement :
Copper reacts with nitric acid to produce nitrogen dioxide.
Which one of the following is not true of metal :
Metal will have 1 or 2 or 3 electrons in their valence shell.
Extraction of moderately reactive elements is done by _______ and _______ method.
Explain concept with example/explain with the help of a balanced equation.
Calcination
