Why is iron more reactive than gold

Chemical properties of gold

Gold: extraordinary metal with extraordinary capabilities

Gold is one of the mineral resources on earth that are only available in very small quantities. Its rare occurrence and also its special shine were the reason why gold became the most important money and valuable metal in the history of mankind over time. In addition to its special importance for jewelry production and the financial world, the precious metal also plays a role because of it exceptional chemical and physical properties an important role as a material for industry.

Basic chemical properties of gold

“Au” is the chemical symbol for gold

Basically, gold is a chemical element. The Latin name for gold is “aurum”. This is derived from this name chemical symbol "Au" for gold. In the periodic table, gold has the atomic number 79 in group 11. Like all chemical elements with atomic numbers 21 to 30, 39 to 48, 57 to 80 and 89 to 112, gold is one of the so-called “transition elements” or also "Transition metals", because all those elements of these atomic numbers are firstly metals and secondly at these points in the periodic table there is a transition to an increasing number of electrons in the electron shell. Furthermore, gold, such as plutonium and cesium, is one of the so-called "Pure elements". There is only one isotope for this and therefore only ever occurs in nature with the same number of protons and neutrons in the atomic nucleus.

High corrosion resistance

What makes the precious metal so interesting for industrial and medical purposes is its high corrosion resistance. Gold is also called chemically "inert" called, shows itself to be very sluggish in the reaction with other substances. For example, gold does not react in any way with air and water and does not corrode even if it is exposed to demanding weather conditions for a long time. This high resistance to oxidation makes gold interesting e.g. for the production of electronic control systems for high-end electrical devices. Power components made of gold are extremely resistant to environmental influences and therefore remain conductive for a very long time. Gold is also there very acid-resistant. In dentistry, dental fillings are often made of gold because gold fillings cannot be attacked by acids in the mouth or in food. Even gold teeth cannot harm food acids. Only “royal acid” (three parts concentrated hydrochloric acid and one part nitric acid) can damage gold and dissolve it.

Light yellow gloss and high density

One of the most striking features of gold is certainly its light yellow color and its special shine. Along with copper and cesium, it is one of the extremely rare metals that have a real color. That is also physically striking high density and the associated high weight. The density is astonishing 19.3 g / cm³ (at 20 degrees Celsius). For comparison: At 19.74 g / cm³, plutonium only has an insignificantly higher degree of density. The high density and heavy weight of gold is the reason that it belongs to the group of Heavy metals is attributed.

Low degree of hardness and low melting point

The melting point of gold is 1063 degrees Celsius

Although a heavy metal, gold has an amazing appearance low degree of hardness and is therefore very malleable and downright soft in relation to other metals. The height Ductility (Extensibility) of gold allows the precious metal to be rolled out into very thin layers until it is finally only 0.001 mm thick. One makes this quality for example at Manufacture of gold leaf advantage. The extraordinary elasticity of gold makes it possible, for example, that a fine ounce of gold with only 31.1 grams can be pulled to the unbelievable length of up to 105 kilometers. The low melting point of “only” 1063 degrees Celsius (for comparison: iron melts at 1535 degrees Celsius), it finally makes it possible that gold is also very well suited to melting it down and casting new forms from it.