Malleability of gold

The malleability of gold. An explanation of its unique mode of deformation, J. Nutting and J. L. Nuttall, Gold Bull, 1977, 10, 2. 

The solid metals all have the fee structure, like their predecessors in the periodic table, Ni, Pd and Pt, and they continue the trend of diminishing mp and bp. They are soft, and extremely malleable and ductile, gold more so than any other metal. One gram of gold can be beaten out into a sheet of 1.0m only 230 atoms thick (i.e. 1 cm to 18 m ) likewise Ig Au can be drawn into 165 m of wire of diameter 20/um. The electrical and thermal conductances of the... 

The fabrication and characterization of atomic metal contacts have been based mainly on electro-deposition/dissolution [182] and break junction techniques (see review [134] and literatures cited therein). In particular, gold nanocontacts have been studied in great detail, due to the chemical inertness of the material, the malleability and ductility of gold. The processes of formation, evolution, and breaking of gold atomic contacts leads to step-like features in the current-distance curves [188, 189]. The abrupt changes in the current (conductance) response were... 

Gold is a soft, malleable, ductile, dense metal with a distinctive yellow color. It is almost a heavy as lead, and both can be cut with a knife. One ounce of gold can be beaten and pounded into a thin sheet that is only a few molecules thick and that will cover over 300 square feet of surface. Although gold is chemically nonreactive, it will react with chlorine and cyanide solutions and can be dissolved in aqua regia. Its melting point is 1,064.4°C, its boiling point is 2,808°C, and its density is 19.3 g/cm (as compared to lead s density of 11.35 g/cm ). 

What is it about gold that makes it so attractive and so useful Gold is not very hard a knife can easily scratch pure gold and it is very heavy or even dense for a metallic mineral. Some of the other characteristics of gold are ductility, malleability and sectility, meaning it can be stretched into a wire, pounded into other shapes, and cut into slices. Gold is the most ductile and malleable element on our planet. It is a great metal for jewellery because it never tarnishes. 

A solution of auric chloride containing 3 to 5 per cent, of gold and a current-density of 1000 amperes per square m tre are usually employed, but Rose has found that with a current-density of 5000 amperes per square m tre an electrolyte with 20 per cent, of gold yields a coherent deposit capable of being readily washed, and malleable after melting. By this modification the time required for solution of the anode is reduced from one week to one day. 

It is hard to imagine a world without aluminum-based materials. From the foil that we wrap leftovers with, to the cans that house beverages and deodorant aerosols, our world is inundated with applications for aluminum. The widespread use of this metal is a direct result of its availability - 8.3 wt% in the earth s crust, making it the most naturally abundant metal. The malleability of A1 is second only to gold, and it possesses other desirable characteristics such as nonsparking, high thermal/electrical conductivity, corrosion resistance, and high ductility. 

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