1, ductility: one ounce of gold can be pulled to 50 Li Long, and its ductility makes it easy to cast, so it is a good choice for making jewelry. Of all metals, it has the greatest tensile force. Second to none. Very thin gold foil that can be easily rolled up can be produced. An ounce of gold can be hammered as thin as four millionths of a foot, with an area of 100 square foot. The ancients hammered it into thin slices and made it into decorations for temples and palaces. All these can explain the flexibility and ductility of gold.
2. The color of gold is golden yellow, which has a metallic texture and is not easy to decompose. The density is 19.3g/cm3 and the melting point is1064.4℃; Good ductility, can be pressed into thin foil, and has extremely high heat and thermal conductivity. Pure gold has a resistance of 2.4P and good chemical resistance, so it is the best electroplating material.
3. As a precious metal, gold has good physical properties. "Real gold is not afraid of fire" means that gold has high chemical stability and is not easy to react with other substances, so there is no need to worry about oxidation and discoloration. Even in the molten state, it will not be oxidized and discolored, and it will still be golden yellow after cooling. High density and heavy feel. It has good toughness and ductility and good electrical conductivity. The color of pure gold is bright yellow, but it changes greatly when mixed with other metals, such as dark red gold-copper alloy and light yellow or grayish white silver-containing alloy. Gold is easily ground into powder, which is why gold is dispersed in nature. Pure gold jewelry is also easy to wear and lose weight.
4. The atomic number of gold in Mendeleev's periodic table is 79, which means that the nucleus of gold contains 79 positively charged protons. At the same time, due to the half-full rule, gold has good chemical stability. In the metal market, gold and metals such as ruthenium, rhodium, palladium, osmium, iridium and platinum are collectively called precious metals.
Although gold is a very soft metal, it is not as good as lead and tin. Nail prints can be painted on pure gold. This softness makes gold very easy to process. But this is not ideal for the manufacturers of decorations, because it is easy to scratch the decorations, make them lose their luster and even affect their appearance. Therefore, when gold is used to make jewelry, copper and silver are usually added to improve its hardness. Although gold itself is non-corrosive, it has a strong chemical affinity with sulfide, and it is easy to adsorb hydrogen sulfide acid gas in the air, and its surface may be dark, such as orange, brown and red. The production of gold products needs to go through many complicated processes.