<Ol> <Li> ^ Jump up to: Z is the standard symbol for atomic number; C is the standard symbol for heat capacity; and χ is the standard symbol for electronegativity on the Pauling scale . </Li> <Li> Jump up ^ Unless otherwise indicated, elements are primordial--they occur naturally, and not through decay . </Li> <Li> ^ Jump up to: The isotopic composition of this element varies in some geological specimens, and the variation may exceed the uncertainty stated in the table . </Li> <Li> ^ Jump up to: The isotopic composition of the element can vary in commercial materials, which can cause the atomic weight to deviate significantly from the given value . </Li> <Li> ^ Jump up to: The isotopic composition varies in terrestrial material such that a more precise atomic weight cannot be given . </Li> <Li> ^ Jump up to: The value listed is the conventional atomic - weight value suitable for trade and commerce . The actual value may differ depending on the isotopic composition of the sample . Since 2009, IUPAC provides the standard atomic - weight values for these elements using the interval notation . The corresponding standard atomic weights are: <Ul> <Li> Hydrogen: (1.00784, 1.00811) </Li> <Li> Lithium: (6.938, 6.997) </Li> <Li> Boron: (10.806, 10.821) </Li> <Li> Carbon: (12.0096, 12.0116) </Li> <Li> Nitrogen: (14.00643, 14.00728) </Li> <Li> Oxygen: (15.99903, 15.99977) </Li> <Li> Magnesium: (24.304, 24.307) </Li> <Li> Silicon: (28.084, 28.086) </Li> <Li> Sulfur: (32.059, 32.076) </Li> <Li> Chlorine: (35.446, 35.457) </Li> <Li> Bromine: (79.901, 79.907) </Li> <Li> Thallium: (204.382, 204.385) </Li> </Ul> </Li> <Li> Jump up ^ Helium does not solidify at a pressure of one atmosphere . Helium can only solidify at pressures above 25 atmospheres, which corresponds to a melting point of absolute zero . </Li> <Li> Jump up ^ The atomic weight of commercial lithium can vary between 6.939 and 6.996--analysis of the specific material is necessary to find a more accurate value . </Li> <Li> Jump up ^ This element sublimes at one atmosphere of pressure . </Li> <Li> ^ Jump up to: The element does not have any stable nuclides, and a value in brackets, e.g. (209), indicates the mass number of the longest - lived isotope of the element . However, four such elements, bismuth, thorium, protactinium, and uranium, have characteristic terrestrial isotopic compositions, and thus their standard atomic weights are given . </Li> <Li> ^ Jump up to: This element is transient--it occurs only through decay . </Li> <Li> ^ Jump up to: This element is synthetic--the transuranic elements 95 and above do not occur naturally, but they can all be produced artificially . </Li> <Li> ^ Jump up to: The value has not been precisely measured, usually because of the element's short half - life; the value given in parentheses is a prediction . </Li> <Li> Jump up ^ With error bars: 357 K . </Li> <Li> Jump up ^ This predicted value is for liquid oganesson, not gaseous oganesson . </Li> </Ol> <Li> ^ Jump up to: Z is the standard symbol for atomic number; C is the standard symbol for heat capacity; and χ is the standard symbol for electronegativity on the Pauling scale . </Li> <Li> Jump up ^ Unless otherwise indicated, elements are primordial--they occur naturally, and not through decay . </Li> <Li> ^ Jump up to: The isotopic composition of this element varies in some geological specimens, and the variation may exceed the uncertainty stated in the table . </Li>

Where are solids located on the periodic table