There is a very rare metal, which is more expensive than gold, about 1000 yuan each, and there is no one. Its texture is very soft and its hardness is very low. It is the easiest metal to cut in the world, but it has a bad temper. When it comes to air, it will start to be natural, and when it comes to water, it will explode directly. Although this role is somewhat unpleasant, it looks beautiful, its face value is absolutely enough, and it has a golden luster. Although it looks like gold, it has a low melting point and can be melted into liquid metal in the palm of your hand. This is cesium, a very active metal.

Can only be put into a special dark cloth, which is made of borosilicate glass. Because it can't touch the air, it needs to be filled with hydrogen, and it can't be opened directly when it needs to be tested. It needs to be taken out in kerosene and needs to be very careful. Once exposed to the air, it will explode instantly. However, although cesium has a bad temper, it is very afraid of kerosene. Once he comes into contact with kerosene, he will immediately shed his golden cesium coat and become a mass of black mud. This is because kerosene contains impurities such as water and oxygen, which will cause cesium to be covered by oxides and peroxides. Because of its low hardness, cutting cesium in kerosene is like cutting butter, and it doesn't need much effort at all.

However, this is very dangerous. If a dark cloth containing cesium is thrown at a wet wall, it will explode instantly and will be oxidized and burned quickly after contacting with air. At the same time, the flame it burns is also different from ordinary flame, which is because of cesium ions. If you put it on a flammable paper towel, you can distinguish the difference between the two kinds of flames more clearly. That year, German scientists Robert William and gustav robert kirchhoff used this change to discover cesium.

German scientist gustav robert kirchhoff knows that he has just invented a spectral analyzer that can separate light. So they cooperated and came up with a method to find Camellia chrysantha by spectral analysis. The discovery of cesium is the application of this method itself. A bottle of mineral water from Sweden was put on the flame in bunsen burner, and then its composition was analyzed by spectrum analyzer. It found the spectra of potassium, sodium, calcium, lithium and other elements in water, but two blue cesium rays were very close. Through repeated experiments, they determined that this is a new alkali metal element and named it type C, which means sky-blue cesium. Although cesium has a bad temper, it will explode when it meets water and air. But its use is also very important. The definition of world time is determined by the time that cesium atoms move around atoms, which is widely used in various high-tech industries such as medicine, aerospace and so on.