Which half-reaction is most easily oxidized?

answer options:
al3+ + 3e- al = -1.66 v
cu2+ + 2e- cu = 0.34 v
fe3+ + e- fe2+ = 0.77 v
na+ + e- na = -2.71 v
pb2+ + 2e- pb = -0.13 v

Which half-reaction is most easily oxidized?

Na^+ + e → Na= -2.71 V (D for plato users)

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.