i still could not understand REDOX REACTIONS.

Redox reactions are the reactions in which oxidation and reduction both occur simultaneously.

Redox reactions are concerned with the transfer of electrons between species.

 

Oxidation refers to the loss of electrons, while reduction refers to the gain of electrons. Each reaction by itself is called a "half-reaction", simply because we need two (2) half-reactions to form a whole reaction. In notating redox reactions, chemists typically write out the electrons explicitly: Cu (s) ----> Cu²⁺ + 2 e^-  

 

2 Ag⁺ (aq) + 2 e^- ------> 2 Ag (s)

 

Here, two silver ions (silver with a positive charge) are being reduced through the addition of two (2) electrons to form solid silver. The abbreviations "aq" and "s" mean aqueous and solid, respectively. We can now combine the two (2) half-reactions to form a redox equation: