International Committee on Chemical Elements

M refers to the table of Radioactive Constants compiled by Meyer, Jakrb. Madiocikt. JUlefdron, 1920, i7 SO I.O. refers to tiie tables given by the International Committee on Chemical Elements, see J. Amer. dhtm, jS oc., 1923, 45, 867 exceptions are indicated hy footnotes. See also this series, Vol. ITT, Paaii I., Table of Constants of the Uraninm-Radinm Series. 

The scientific world accepted the term emanation. However, in 1910 Ramsay suggested the name niton from a Greek word meaning shining . The reason was the appearance of the condensed, liquid element. However, the International Committee on Chemical Elements decided in 1923 in favor of the name radon, expressing its daughter relationship to radium. 

Aston et al., 1923] F. W. Aston et al. Report of the International Committee on Chemical Elements, Journal of the American Chemical Society 45, 866-74, 1923. 

Since 1888 Brauner attempted to put through, jointly with the American chemist F. P. Venable (1856-1934) and other chemists, the atomic weight of oxygen (16) as standard for calculation of relative atomic weights of elements this proposal was only accepted in 1900 at the 4th International Congress of Applied Chemistry in Paris. In the years between 1921 and 1930 Brauner was member of the International Committee on Chemical Elements and president of its subcommission on atomic weights. 

Aston Frederick W., Baxter, G. P., Brauner, B., Debieme, A., Leduc, A., Richards, Soddy, T. W. F., Urbain, G. 1923. "Report of the International Committee on the Elements." Journal of the American Chemical Society 45 867-874. 

At the beginning of the twentieth century, the International Committee on Atomic Weights (ICAW) was formed. Although the ICAW did not set internationally approved names, a name with an atomic weight value in their table lent support for the adoption of that name by the chemical community. Twenty years later, the ICAW became a part of the International Union of Pure and Applied Chemistry (lUPAC) when it was formed. lUPAC was called the International Union of Chemistry in those early days. In 1949, the responsibility for acceptance of the name of a chemical element was given by lUPAC to its Commission on Nomenclature of Inorganic Chemistry (CNIC). 

The risk to health from chemicals in food can be assessed by comparing estimates of dietary exposure with recommended safe levels of exposure. For most metals and other elements, these are the Provisional Tolerable Weekly Intakes (PTWIs) and the Provisional Tolerable Daily Intakes (PTDIs) recommended by the Joint Expert Committee on Food Additives of the Food and Agricultural Organisation of the United Nations and the World Health Organisation International Programme on Chemical Safety (JECFA). The European Commission s Scientific Committee on Food has established other relevant safe levels. These are Acceptable Daily Intakes (ADIs) for chemicals added to food, and Tolerable Daily Intakes (TDIs) for chemical contaminants. The use of the term tolerable implies permissibility rather than acceptability. All the above recommendations are estimates of the amount of substance that can be ingested over a lifetime without appreciable risk, expressed on a daily or weekly basis as appropriate. 

The Values of the Atomic Weights. The 1949 atomic iveights of the elements, as announced by the International Committee on Atomic Weights, are given in Table 4-2. The use of these values in carrying out chemical calculations is discussed in Chapter 7. 

Controversy about the first synthesis of new chemical elements in the trans-lawrencium region has recently been resolved by a joint lUPAC and lUPAP (International Union of Pure and Applied Physics) committee. CNIC has assigned names that appear to have been internationally accepted for these elements. Although I have relied on the lUPAC/IUPAP document to discuss elements up to Meitnerium, for elements above Z = 109, the analysis provided is strictly my own due to my reading and interpretation of the scientific literature. 

The mode of inspection has been vigorously debated. On 21 July 1982, the Soviet Union presented its Basic Provisions on a CW Convention before the Committee on Disarmament. It proposed an agreed number of regular visits on a quota basis as distinct from the continuous monitoring favoured by the United States. Only on 2 April 1984 did the Soviet Union accept that the destruction of certain types of chemical weapons would have to be monitored by the continuous presence of inspection teams." Indeed, systematic international on-site inspection, involving a routine presence without any element of suspicion, should build confidence in the regime established by the convention. The number of inspectors could be reduced by the on-site emplacement of chemical and physical instruments. 

It is regrettable that, in the past, different symbols have been adopted in compilations, but it is expected that, in the future, symbols advocated by I UP AC will be employed universally and that SI will be used for the units. To secure a further unification in thermodynamic tables, the International Council of Scientific Unions (ICSU) and the Committee on Data for Science and Technology (CODATA) set up in 1968 a Task Group on Key Values for Thermodynamics. The first objective of the Task Group is to prepare a set of values of the basic thermodynamic properties of a number of chemical species, to be agreed internationally. The set is to include the elements in both standard and monatomic gaseous states, aqueous ions, and simple compounds. ... 

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