|
Gold
|
| Au |
| Atomic Number |
79 |
| Atomic Mass |
196.966569 |
| Atomic radius |
0.134 |
| Ionization energy |
889 |
| Electronic config |
2,8,18,32,18,1 |
| Principal Valency |
+2 |
| Density g/cm3 |
19.32 |
| Melting point oC |
1064.18 |
| Boiling point oC |
2856 |
| Type of Element |
Metal |
| Electronegativity |
2.4 |
| Appearance |
Yellow solid |
| Block |
d-block |
| Period |
6 |
| Group |
11 |
| No of Isotopes |
37 |
| Occurrence |
Free and combine |
| Abundance in ppm |
0.004 |
| Year of Discovery |
N/A |
|
| INTRODUCTION |
| Gold is a soft, dense, bright yellow metallic element. It is the most malleable and ductile of all the metals in its pure form. It can easily be beaten or hammered to a thickness of 0.000013 cm, and 29 g could be drawn into a wire 100 km (62 mi) long. |
| Gold has a high luster and a good conductor of heat and electricity. It is extremely inactive. It is unaffected by air, heat, moisture, and most solvents. It will, however, dissolve in aqueous mixtures containing various halogens such as chlorides, bromides, or some iodides. |
| EXTRACTION |
| OXIDATION STATES |
| +5,+4,+3,+2,+1,-1,-2 (amphoteric) |
| ELEMENT CATEGORY |
MAJOR SOURCE |
| Copper / coinage Group |
Quartz veins, Electrum, Gold amalgam |
| EXAMPLES OF COMPOUND PRESENT |
| Potassium gold cyanide |
| ECONOMIC IMPORTANCE |
| * Gold is used in dentistry and radioisotopes of gold are used in biological research and in the treatment of cancer. |
| * Due to its relative rarity, gold became used as currency and as a basis for international monetary transactions. |
| * Precipitate of finely divided gold and stannic hydroxide formed by the interaction of auric chloride and stannous chloride, is used in coloring ruby glass. |
| * Gold is mostly used for jewelry due to its value, beauty and resistance to corrosion. |
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Fri May 26 , 2017
The most awaited competitive exam of all times i.e. the civil services(CS) preliminary examination 2017 is going to be conducted on 18 June 2017 by the Union Public Service Commission( UPSC). The prelims always draw horde of candidates. For selecting candidates the UPSC follow a 3 step selection process that […]
