How do weedkillers work?​

the have a special chemical in them causing the plant to descintagrate over time from the special chemical :)

Explanation:

A physical change, such as a state change or dissolving, does not create a new substance, but a chemical change does.In a chemical reaction, the atoms and molecules that interact with each other are called reactants.In a chemical reaction, the atoms and molecules produced by the reaction are called products.In a chemical reaction, only the atoms present in the reactants can end up in the products. No new atoms are created, and no atoms are destroyed.In a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.
Below is the example of a chemical reaction that takes place during photosynthesis.

Plants apply a chemical reaction called photosynthesis to convert carbon dioxide and water into food (glucose) and oxygen. It's one of the most common everyday chemical reactions and also one of the most important, since this is how plants produce food for themselves and animals and convert carbon dioxide into oxygen.

6 CO2 + 6 H2O + light → C6H12O6 + 6 O2