Lithium, a chemical element, is a metal with strong metal activity (cesium is the most metal). Its chemical symbol is Li, and its atomic number is 3. Two of the three electrons are distributed in the K layer, and the other is in the L layer. Lithium is the lightest of all metals. Because of its high charge density and stable helium type double electron layer, lithium is easy to polarize other molecules or ions, but not itself. This will affect the stability of it and its compounds.
Although the hydrogen standard potential of lithium is the most negative, reaching -3.045, the lithium hydroxide solubility is not large and the exothermic reaction between lithium and water cannot melt lithium, so the reaction between lithium and water is not as violent as sodium. After a period of time, the nitrogen oxide film on the lithium surface is dissolved, making the reaction more intense. It is easy to react with hydrogen at about 500 ℃ to produce lithium hydride. It is the only alkali metal that can generate hydride that is stable enough to melt without decomposition. Its ionization energy is 5.392eV. It can combine with oxygen, nitrogen, sulfur, etc. It is the only alkali metal that can react with nitrogen at room temperature to generate lithium nitride (Li ｜ N). Darkened by oxidation. If lithium is thrown into concentrated sulfuric acid, it will float rapidly on sulfuric acid, burn and explode. If lithium and potassium chlorate are mixed (vibrated or ground), it may also react explosively.
