metal

Is Carbon a metal, nonmetal or metalloid

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Is Carbon a metal, nonmetal or metalloid

The food you eat, the clothes you wear, the cosmetics you use, the fuels you use to run automobiles are all the compounds of carbon.
Carbon was discovered in prehistory and it was known to the ancients.
They used to manufacture charcoal by burning organic material.
Carbon is a non-metal. It belongs to the fourteenth group or IV A group in the modern periodical table. The elements of this group have four electrons in the valence shell.
Let us write the electronic configuration of Carbon (6C).
Atomic number of carbon is 6.
Electronic configuration of carbon (ground state) 6C: 1s2 2s2 2p2. To get the octet in its outer shell it has to gain four more electrons to form C4-. The electronegativity of carbon is only 2.5 and its nucleus has only six protons. Therefore it would be difficult for a nucleus with six protons to hold ten electrons. Hence, carbon cannot form C4- ions so easily.
If carbon loses four electrons from the outer shell, it has to form C4+ ions. This requires huge amount of energy which is not available normally.
Therefore C4+ formation also is a remote possibility. Carbon has to satisfy its tetravaiency by sharing electrons with other atoms. It has to form four covalent bonds either with its own atoms or atoms of other elements.
The possibility of bonds formation by a carbon atom is as:
a) i. Four single covalent bonds, with atoms of same element like hydrogen, Chlorine.
Is Carbon a metal, nonmetal or metalloid 1
ii. Four single covalent bonds with atoms of different elements ;
Is Carbon a metal, nonmetal or metalloid 2
b) Carbon atoms may form one double bond and two single bonds
Is Carbon a metal, nonmetal or metalloid 3
c) Carbon atom may form one single bond and a triple bond
Eg: H–C ≡ C–H or CH3–C ≡ N or carbon atoms may also form two double bonds as in CH2 = C = CH2.

Carbon atomic number is 6. Its mass number is 1.20. Its atomic mass is 12.011. Its melting point is 3550ºC and boiling point is 4830ºC. It occurs in free state as well as in combined state. 70% of our body is made up of carbon. It forms largest number of compounds. The earth crust contains only 0.02% of carbon.

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Metallurgy

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Metallurgy

The process of extracting metals from their ores and refining them for use is known as metallurgy. In other words, the process of obtaining a metal from its ores is called metallurgy of the metal.
Common terms used in discussing metallurgical operations :
1. Charge : The mixture of materials fed to a furnace for obtaining the metal is called charge.
2. Dressing of the ore : The removal of impurities associated with ore is called dressing or enrichment of the ore.
3. Calcination : The process of heating a metal-rich ore to a high temperature to convert the metal into its oxide, either in absence or insufficient supply of air is called calcination.
4. Roasting : The process of heating a finely ground ore to a high temperature in excess of air is called roasting. Roasting converts the metal present in the ore to its oxide.
5. Flux : A flux is a substance that is mixed with the fumance charge (calcined or roasted ore and coke) to remove the infusible impurities present in the ore.
6. Slag : Flux combines with the infusible impurities to convert them into a fusible substance called slag. Being light, slag floats over the molten metal and is removed from there.
Impurities present in metal oxides may be acidic or basic. For acidic impurities, such as SiO2 or P2O5, a basic flux (e.g., CaO) is added to the charge. If basic impurities such as MnO are present, silica is added to the charge.

ImpurityFluxSlag
SiO2       +CaO  →CaSiO3
P2O5       +3CaO   →Ca3(PO4)2
MnO       +SiO2  →MnSiO3

7. Gangue or matrix : The ore mined from the earth’s crust contains some unwanted substances or impurities, such as sand, rocky or clayey materials. These substances are called gangue or matrix. The gangue has to be removed before the process of extraction of metals starts.
8. Smelting: The process of obtaining the metal by reducing its oxide ore with coke is known as smelting.
Principles of metallurgy
The extraction of a metal from its ore depends upon the reactivity of the metals.
1. Metals at the top of the activity series (K, Na, Ca, Mg, etc.) are highly reactive. They do not occur in the free state. They are extracted by the electrolysis of the molten ore.
2. Metals in the middle of the activity series (Zn, Fe, Pb, etc.) are moderately reactive. These are obtained by roasting and calcination of their sulphide or carbonate ore.
3. Metals at the bottom of the activity series (Au, Ag, Pt, Cu) being the least reactive are found in the free state. Copper and silver also occur as their sulphide or oxide ores. These are obtained by the process of roasting.

How metal is formed in the Earth

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How metal is formed in the Earth

Metals occur in nature in free state or in combined state. A metal is said to occur native or free when it is found in nature in the metallic state. For example, gold may be found in nature as metal. This is because gold when left exposed to air practically does not undergo any change. It is not reacted upon by moisture, oxygen and carbon dioxide of the air. Thus, those metals which remain unaffected by moisture, oxygen and carbon dioxide of the air can occur native or free. In other words, the unreactive metals occur in nature in free state because of their low reactivity towards chemical reagents. Another example of an unreactive metal is silver.
The reactive metals, i.e., the metals which react with moisture, oxygen, carbon dioxide or other chemical reagents, are not found in nature in free state, but in combined state in the form of compounds.
How metal is formed in the Earth 1Metals usually occur in combination with nonmetallic elements. The native occurrence is comparatively rare.

Minerals and Ores :
Metal-bearing substances, found in the earths crust, are called minerals. In other words, the solid compounds of metals occurring in nature are called minerals. For example, NaCl, KCl, CaCO3, MgCO3, ZnS, Cu2S, Fe2S3 etc., which are found in nature are minerals.
Some minerals and their occurrence in India are given below.

MetalMineralsPlaces of occurrence in India
1. Sodium

2. Magnesium

3. Calcium

4. Aluminium

5. Copper

6. Zinc

7. Manganese

8. Iron

Tincal, borax

Dolomite, magnesite

Gypsum

Bauxite

Chalcopyrites or copper pyrites, malachite

Zincblende

Pyrolusite

Haematite

Ladakh (Kashmir)

Tamil Nadu

Rajasthan, Tamil Nadu, Jammu  and Kashmir

UP, Maharashtra,’MP, Orissa

Jharkhand, Orissa, MP

Rajasthan

Maharashtra, Karnataka and Jharkhand

Jharkhand and Karnataka

Ores :
The minerals from which metals can be obtained on a commercial scale are called ores. In other words, the minerals from which metals can be extracted profitably are called ores. Both bauxite
(Al2O3.2H2O) and clay (Al2O3.2SiO2 . 2H2O) are minerals of aluminium. However, it is bauxite that is chiefly used to obtain aluminium commercially. So, bauxite, not clay, is an ore of aluminium. Thus:
(i) All ores are minerals, but all minerals are not ores.
(ii) An are is rich in the amount of the metal. The amount of foreign materials or impurities is low in an ore.
Different types of ores: 
The different types of ores that are used in the extraction of metals are listed below.
1. Oxides : Copper, aluminium, zinc, tin, iron, etc., occur as oxides.
2. Sulphides : Silver, copper, zinc, mercury, lead, iron, etc., occur as sulphides.
3. Carbonates : Sodium, copper, calcium, magnesium, zinc, lead, iron, etc., occur as carbonates.
4. Sulphates : Sodium, calcium, magnesium, lead, etc., occur as sulphates.
5. Halides : Sodium, calcium, silver, etc., occur as halides.
6. Phosphates : Calcium occurs as phosphate.