For example, divide a piece of glass into two halves, then take one of the two halves and divide it into two halves again. Keep dividing and dividing. In the end, there will be a substance that maintains this kind of substance (that is, the example given) Such a smallest thing with the properties of glass cannot be divided any further. If it is divided further, it will not be glass, so it is called a molecule. So what is this thing that maintains this property and what is its original composition? ? This is composed of basic elements such as Na, O, and Si. Its original components are these three, and this component is also inseparable. It is an element that maintains its most original properties, so it is called an atom. The word molecule in English is molecule, which comes from the Latin moles, which means "very small unit of matter". The word atom in English is atom, which comes from the Greek ?τομο?, which means indivisible. . . . . In fact, there is really no reason for the name. After all, scientific naming does not require fortune-telling, just call it this.