Gold is golden yellow. The brighter the color, the higher the fineness, the softer the hardness and the truer it is.

2. The specific gravity of gold is higher than that of ordinary metal, the standard specific gravity is 19.3, and that of ordinary metal is lower than 19.3.

Third, gold does fall freely from a height, and only when it does not bounce back, it means it is highly pure gold.

Four gold jewelry as for the barbecue in the fire, the color has changed, not real gold.

Five? Pure gold will not change in dilute nitric acid, but the quality of gold-silver alloy will decrease in dilute nitric acid, and the obtained liquid will be colorless, while brass will be completely dissolved in nitric acid, and the obtained liquid will be blue (because of Cu(NO3)2), so it can be tested with dilute nitric acid.

Extended data

Pure gold refers to 24K gold, which means its gold content is 100%. But there is no 24K gold in the world. Therefore, if there is gold marked "24K gold" or "pure gold" on the market, it is not true.

The content of pure gold in decorative gold is called "gold position", which is Karat in English, so it is called K gold. Generally speaking, pure gold is 24K, which means that the gold content is 100% in theory. Therefore,

The gold content of 22K is 9 1.6%, 20K is 83.3%, 18K is 75%, and 14K is 58.3%?

K gold refers to the alloy of gold mixed with other metals. Kai is the unit of measurement of K gold, which divides pure gold into 24 parts. According to the gold content in jewelry, it is divided into different K gold, so 24K refers to pure gold.

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