The relative strengths of reducing agents can be inferred from their standard electrode potentials. The strongest reducing agents are shown in the standard electrode table. Lithium, having the largest negative value of electrode potential, is the strongest reducing agent. Lithium is the strongest reducing agent though it has the highest ionization energy in its group. Three common reducing agents are sodium borohydride (NaBH4), lithium aluminum hydride (LiAlH4), and diisobutyl aluminum hydride (DIBAH). Oxygen is, therefore, an oxidizing agent. Oxidizing and reducing agents, therefore, can be defined as follows. Oxidizing agents gain electrons. Reducing agents lose electrons. Hydrogen peroxide acts as an oxidizing and reducing agent, depending upon the nature of the reacting species. Examples of substances that are common reducing agents include alkali metals, formic acid, oxalic acid, and sulfite compounds. Answer and Explanation: Precious metals like gold, silver, and platinum are poor reducing agents, i.e., they get reduced easily. Elemental sodium is a good reducing agent, as it belongs to group-I, and elements of group-I have one electron in their valence sheet. So, they lose 1 electron readily to attain noble gas configuration, hence undergoing oxidation (i.e., loss of electron) and acting as a good reducing agent. Chlorine can take electrons from both bromide ions and iodide ions. Bromine and iodine can't return those electrons from the chloride ions formed. That means Chlorine is a more powerful oxidizing agent than bromine or iodine. Similarly, bromine is a more powerful oxidizing agent than iodine. If you are looking for high quality, high purity and cost-effective water-reducing agent, or if you require the latest price of water-reducing agent, please feel free to email contact mis-asia.