In 1803,(John Dalton) scientists British atomic for theory proposed use To explain the change of Mass before and after made reaction. including the ratio by mass of the elements the combined is a compound. have essence is as follows
- Element consists of tiny particles called Atoms. cannot be separated from each other have.
- Atoms cannot be rebuilt or lost have.
- Atoms of the same element have the equal mass and the same features but is different from the atoms of other elements.
- The compound is Aggregation between atoms of different chemical species. With the simple ratio Or have little number
-- Atom of element two type up. will gathered by ratio Different. for to will be is compound have many type.