Gold
Gold (Au), chemical element, a dense lustrous yellow precious metal of Group 11 (Ib), Period 6, of the periodic table. Gold has several qualities that have made it exceptionally valuable throughout history. It is attractive in color and brightness, durable to the point of virtual indestructibility, highly malleable, and usually found in nature in a comparatively pure form. 
The history of gold is unequaled by that of any other metal because of its perceived value from earliest times.
Gold Properties – What are the Physical Properties of Gold?
What are the Physical Properties of Gold? The Physical properties of Gold are the characteristics that can be observed without changing the substance into another substance. Physical properties are usually those that can be observed using our senses such as color, luster, freezing point, boiling point, melting point, density, hardness and odor. The Physical Properties of Gold are as follows:
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the Physical Properties of Gold? |
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| Color | Bright Yellow |
| Luster | It has a shine or glow |
| Ductility | It can be beaten into extremely thin sheets of gold leaf |
| Malleability | Capable of being shaped or bent |
| Conductivity | Good electrical conductor |
| Solubility | Solubility (ability to be dissolved) |
| Hardness | A relatively soft metal, gold is usually hardened by alloying with copper, silver, or other metals. |
| Density | It is a dense metal |
| Melting point | It melts at 1065°C |
Gold Properties – What are the Chemical Properties of Gold?
What are the Chemical Properties of Gold? They are the characteristics that determine how it will react with other substances or change from one substance to another. The better we know the nature of the substance the better we are able to understand it. Chemical properties are only observable during a chemical reaction. Reactions to substances may be brought about by changes brought about by burning, rusting, heating, exploding, tarnishing etc. The Chemical Properties of Gold are as follows:
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What are the Chemical Properties of Gold? |
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| ChemicalFormula | Au |
| Activity | Gold is chemically inactive, it’s extremely resistant to chemical action |
| Compounds | Ready reducibility from compounds to metal. Auric chloride and chloro-auric acid are its most common compounds. |
| Reactivity withacids | Aqua regia, a mixture of nitric and hydrochloric acids, has the ability to dissolve gold |
| Isotopes | It has one stable isotope,197Au |
| Reactivity with Non-metals | Gold does not react with the Non-metals, except for halogens, with which it forms halides |
| Alloys | Silver and platinum |
Gold Physical Data
- Density (g/cc): 19.3
- Melting Point (°K): 1337.58
- Boiling Point (°K): 3080
- Appearance: soft, malleable, yellow metal
- Atomic Radius (pm): 146
- Atomic Volume (cc/mol): 10.2
- Covalent Radius (pm): 134
- Ionic Radius: 85 (+3e) 137 (+1e)
- Specific Heat (@20°C J/g mol): 0.129
- Fusion Heat (kJ/mol): 12.68
- Evaporation Heat (kJ/mol): ~340
- Debye Temperature (°K): 170.00
- Pauling Negativity Number: 2.54
- First Ionizing Energy (kJ/mol): 889.3
- Oxidation States: 3, 1. The oxidation states -1, +2 and +5 exist but are rare.
- Lattice Structure: Face-Centered Cubic (FCC)
- Lattice Constant (Å): 4.080
- Specific Gravity (20°C): 18.88
- CAS Registry Number: 7440-57-5
