Convert 6.73 kg to lb

The name of the ion, s2-, is: sulfurous ion sulfide ion sulfur ion sulfate ion

One does not belong why? ice, gold ,wood ,diamond and table salt

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange