Consider the following electrochemical cell notation: M(s) / M2+ (aq)// H+ (aq)/ H2(g). The value of the electrode potential is positive when?

A. electrons flow from the metal electrode, M(s) to hydrogen electrode, H2(g)
B. electrons fow from hydrogen electrode, H2(g) to metal electrode, M(s)
C. the flow of current is high
D. there is equilibrium between the flow of electrons from the hydrogen electrode, H2(g) to metal electrode, M(s)

Correct Answer: Option A

A. electrons flow from the metal electrode, M(s) to hydrogen electrode, H2(g)