Chapter 23.4, Problem B23.1P

(a)

Interpretation Introduction

Interpretation:

The central metal ion and its oxidation state of chlorophyll, heme, and vitamin $B_{12}$ has to be identified.

Concept introduction:

Oxidation number: (Oxidation state) A number equal to the magnitude of the charge an atom would have if its shared electrons were transferred to the atom that attracts them more strongly.

(b)

Interpretation Introduction

Interpretation:

The structure similarity between chlorophyll, heme, and vitamin $B_{12}$ has to be identified.