Zirconium
Isotope | Atomic mass (Da) | Isotopic abundance (amount fraction) |
---|---|---|
90Zr | 89.904 6988(8) | 0.5145(4) |
91Zr | 90.905 6402(7) | 0.1122(5) |
92Zr | 91.905 0353(7) | 0.1715(3) |
94Zr | 93.906 313(1) | 0.1738(4) |
96Zr | 95.908 2776(8) | 0.0280(2) |
The atomic weight of Zr has been taken to be Ar(Zr) = 91.22 since 1931, and this value was reconfirmed in 1969 when it was assessed as 91.22(1). Since then, two isotopic composition measurements have been carried out Ar(Zr) = 91.224 with an estimated uncertainty of +0.002 and –0.005, and Ar(Zr) = 91.2235(5).
© IUPAC 2003
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