Electrochemical series is a series of elements or metals. In which metals or elements are arranged in increasing order of their reduction potential. \(E_{H^{+}/H_{2}}^{0}\)=0.  The metals which lies above H have negative reduction potential and they are more reactive than hydrogen whereas metals below hydrogen are less reactive than H and have positive reduction potential. The reduction potential of metal depends upon the following factors(i) sublimation energy (ii) ionisation energy and (iii) hydration energy of ions.