This element was isolated by J. and F. Elhuijar in Vergara in Spain, in 1783. The element has also been called wolfram. In Swedish tung sten means heavy stone. Wolfram comes from the German Wolf(wolf).
Ionization energies
WI 8.0 eV, WII 17.6 eV, WIII 26.1 eV.
In the sun, the equivalent width of WI 4009(6) is 0.013.
Behaviorin non-normal stars
WI was found in one Ap star of the Cr-Eu-Sr subgroup Jaschek and
Brandi 1972) and in another one by Guthrie (1972). Sadakane (1991) found
the 2030(5)
line of WII in the ultraviolet spectrum of one Am star. Danziger
(1965) and Warner (1965) found WI to be enhanced in Ba stars.
Isotopes
W has five stable isotopes, W 180, 182, 183, 184 and 186, and 17 short-lived
isotopes and isomers. The stable isotopes occur in the solar system with the
following frequencies: 0.1%, 26%, 14%, 31% and 29%.
Origin
W 182, 183 and 184 are all produced by the r process and the s process.
W180 is produced only by the p process and W186
only by the r process.
Published in "The Behavior of Chemical Elements in Stars", Carlos Jaschek and Mercedes Jaschek, 1995, Cambridge University Press.