Geological specimens are known in which the element has an isotopic composition outside the limits for normal material.
See table 1 for details of range and original paper for the atomic weight of the element from different sources.
Now, let me recall to you the atomic mass of lithium, sodium and potassium. The main thing I want to tell you is that he arranged these elements in the increasing order of their ATOMIC MASS. However three such elements (Th, Pa, and U) do have a characteristic terrestrial isotopic composition, and for these an atomic weight is tabulated. Calcium (Ca), strontium (Sr) and Barium (Ba) in other triad and, Chlorine (Cl), bromine (Br) and iodine (I) in other triad. , indicates the mass number of the longest-lived isotope of the element. Substantial deviations in atomic weight of the element from that given in the Table can occur.
For radioactive elements the isotope with the longest half-life is quoted in parenthesis. In the other lists the values quoted are those suggested for material where the origin of the sample is unknown. Element Titanium (Ti), Group 4, Atomic Number 22, d-block, Mass 47.867. The standard atomic weights of twelve elements having two or more stable isotopes have variability of atomic-weight values in natural terrestrial materials. Periodic Table of Videos Created by video journalist Brady Haran working with chemists at The University of Nottingham. Previous values may be consulted from the 1993 table, the 1995 table, the 1997 table, the 1999 table, the 2001 table, the 2005 table, the 2007 table, the 2009 table, the 2011 table, the 2013 table, the 2015 table or the 2019 table. World Wide Web version of atomic weight data originally prepared by G. These tables are based on the 2021 table with changes from the 2019 table for the values of Ar, Hf, Ir, Pb and Yb and changes to the uncertainty for Al, Au, Co, F, Ho, Mn, Nb, Pa, Pr, Rh, Sc, Tb, Tm, and Y. 2021 Atomic Weights IUPAC Commission on Isotopic Abundances and Atomic Weights.