空气是由多种分子组成的混合物，其主要成分是氮气和氧气．在正常情况下，气体分子是呈中性的，然而在自然界宇宙射线、紫外线、雷电、风浪、镭和钍等放射性物质作用下，空气中性分子因电离而释放电子，这些自由电子与空气中的一些分子结合就形成了空气负离子．而通常人们... Air is a mixture of many molecules whose main components are nitrogen and oxygen. Under normal circumstances, the gas molecules are neutral. However, under the action of natural cosmic rays, ultraviolet rays, lightning, wind waves, radium, and thorium, the air-neutral molecules release electrons due to ionization. These free electrons and air Some molecules combine to form air anions. And usually people...