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प्रश्न
How many valence electrons are present in metals ?
उत्तर
Metals have 1, 2, 3 valence electrons
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संबंधित प्रश्न
Give reasons.
Carbonate and sulphide ores are usually converted into oxides during the process of extraction.
Name two ores of zinc. Write the names of the chemical compounds present in them and give their chemical formulae.
An element has its electron configuration as 2,8,8,2. Now answer the following questions.
a) What is the atomic number of this element?
b) What is the group of this element?
c) To which period does this element belong?
Define the term : Flux
Compare the process of calcination and roasting.
State the property of the metal being utilized in the following :
| Use of metal | Property |
| Zinc in Galvanization | |
| Aluminium in Thermite welding |
Explain Bayer’s process.
Explain the reactions of nonmetals with water with the help of examples.
Answer the questions on the following passage.
The minerals from which the metal can be separated economically are called ores. Ores contain many types of impurities such as soil, sand and rocky substances along with metal compounds. These impurities are called gangue.
Metals can be extracted from their ores by means of various methods of separation. The process of extraction of metal in a pure state from the ores is also a part of metallurgy.
Ores are taken out from the mines and the gangue is usually separated from the ore at the site itself by various methods. Then the ores are carried out to the place where metals are produced. Here metals are extracted in pure form. Then metals are further purified by different methods of purification. This entire process is called metallurgy. Most metals being reactive do not occur in nature in the free state but are found in combined state as their salts such as oxides, carbonates, sulphides, and nitrates. however, the most unreactive metals that are not affected by air, water and other natural factors like silver, gold, platinum, generally occur in a free state. The compounds of metals that occur in nature along with the impurities are called minerals.
- What are ores?
- Which processes are involved in the branch of metallurgy? What is metallurgy?
- Which metals are found in a free state?
- In what forms are metals found in combined state?
- What is gangue?
Oxides of moderately reactive metals like Zinc, Iron, Nickel, Tin, Copper, etc. are reduced by using:
