Which element has atoms that can form single, double, and triplecovalent bonds with other atoms of the same element?
(1) hydrogen (3) fluorine(2) oxygen (4) carbon

Carbon : 

- 4 single bonds 
- 2 singles and 1 double bonds 
- 2 double bonds 
- 1 single and 1 triple bond

Answerthe half-reaction having the greatest tendency to occur at the anode:     i₂(aq) + 2e⁻  ⇄ 2i⁻  ;   e = +0.53 v======oxidation occurs at the anode. we must therefore find the half-reaction with the greatest tendency to oxidize.the given values of e are reduction potentials (the form of the half-reactions are of reduction).the lower the reduction potential, the higher the potential to oxidize. the half-cell with the lowest reduction potential will have the greatest tendency to oxidize at the anode.the half-reaction having the greatest tendency must be    i₂(aq) + 2e⁻  ⇄ 2i⁻    e = +0.53 vbecause its reduction potential is the lowest out of the three.