Standard atomic weight precise value is acceptable, CIAAW has published a single-number conventional atomic weight that can be used for example in trade. For hydrogen, . The twelve elements are: hydrogen, lithium, boron, carbon, nitrogen, oxygen, magnesium, silicon, sulfur, chlorine, bromine and thallium. By using the abridged value, and the conventional value for the twelve interval values, a short IUPAC-defined value (5 digits plus uncertainty) can be given for all stable elements. In many situations, and in periodic tables, this may be sufficiently detailed. Standard atomic weight The standard atomic weight ("A", a relative atomic mass) is the atomic weight ("A") of a
Standard weight in fish relationships representing a species across its range are used. As fish grow in length, they increase in weight. The relationship between weight and length is not linear. The relationship between length ("L") and weight ("W") can be expressed as: When the equation is for standard weight, the standard weight for a given length is written as W. The exponent "b" is close to 3.0 for most species. The coefficient "a" varies between species. If the exponent "b" is greater than three for a certain fish species, that species tends to become relatively fatter or have more girth as it grows