Atomic Mass of Zinc. Atomic mass of Zinc is 65.409 u. Note that, each element may contain more isotopes, therefore this resulting atomic mass is calculated from naturally-occuring isotopes and their abundance. The unit of measure for mass is the atomic mass unit (amu). One atomic mass unit is equal to 1.66 x 10-24 grams. Molar mass calculations are explained and there is a JavaScript calculator to aid calculations. Chemical Database This database focuses on the most common chemical compounds used in the home and industry. Citing this page. If you need to cite this page, you can copy this text: Kenneth Barbalace. Periodic Table of Elements - Zinc - Zn.
This preview shows page 46 - 49 out of 49 pages. GROUP IB (11) 13. Zinc (/zink/) Symbol: Zn Atomic mass: 65.38 u Atomic number: 30 Electron configuration: Ar 3d104s2 Melting point: 419.5 °C Discovered.
| Isotope | Atomic mass (Da) | Isotopic abundance (amount fraction) |
|---|---|---|
| 64Zn | 63.929 142(5) | 0.4917(75) |
| 66Zn | 65.926 034(5) | 0.2773(98) |
| 67Zn | 66.927 127(5) | 0.0404(16) |
| 68Zn | 67.924 844(5) | 0.1845(63) |
| 70Zn | 69.925 32(2) | 0.0061(10) |
In 1961, the Commission recommended Ar(Zn) = 65.37 based on the chemical determinations. Meanwhile,mass-spectrometric determinations yielded a higher value of Ar(Zn) = 65.387.
In 1971, coulometric determinations yielded Ar(Zn) = 65.377(3), whereupon the Commission changed the recommendedvalue to 65.38(1). Soon, another mass-spectrometric value was published which yielded Ar(Zn) = 65.396(5). Faced with this ongoing discrepancy between chemical and physical values, in 1983 the Commission recommended Ar(Zn) = 65.39(2), explaining that the value was now weighted toward the mass-spectrometric measurement, but the uncertainty included the coulometric measurement. In 2001, Ar(Zn) was changed to 65.409(4) and in 2007 the Commission acknowledged that data influencing the 2001 decision could no longer be supported and recommended the current value of Ar(Zn) = 65.38(2). This change was unique in the sense that for the first time in the history of the Commission, the standard atomic weight (with its uncertainty) was outside the bounds of the previous value.
CIAAW
Zn Atomic Mass Number
Zinc
Ar(Zn) = 65.38(2) since 2007
The name derives from the German zink of unknown origin. It was first used in prehistoric times, whereits compounds were used for healing wounds and sore eyes and for making brass. Zinc was recognized asa metal as early as 1374.
Zinc Chemical Formula
Isotopic reference materials of zinc.