![](https://webonlin.ir/wp-content/uploads/2023/04/2.jpg)
POLYMERS
A polymer is any of a class of natural or synthetic substances composed of very large molecules, called macromolecules, which are multiples of simpler chemical units called monomers.
![](https://webonlin.ir/wp-content/uploads/2023/04/1.jpg)
CHEMICALS
A chemical is any substance that has a defined composition. In other words, a chemical is always made up of the same "stuff".
![](https://webonlin.ir/wp-content/uploads/2023/04/3.jpg)
FERTILIZERS
Fertilizers are organic or inorganic substances containing chemical elements that improve the growth of plants and the fertility of the soil.