Water isotope isomers

Michael Weisberg s water example (Chapter 18) helps to make this point. Ordinary, although purified (but how purified ), water found naturally on the Earth contains typical, percentage-wise predicable isotopic isomers. While most water is composed of ordinary one proton one electron hydrogen, a small percentage is composed of a heavier isotopic isomer of hydrogen one proton-one neutron-one electron, deuterium, or D. We symbolize heavy water, HDO, instead of H20. For many purposes, the water we want to talk about must contain the standard... 

SORPTION OF ORTHO-PARA-SPm ISOMERS AND ISOTOPE ISOMERS OF WATER... 

For pure water ice, we assume that the vibrational free energy of the various H-bond isomers is nearly the same, and that quantum effects on free energy differences between isomers can be neglected. The excellence of these approximations is confirmed by the fact that H2O/D2O isotope effects have very little effect on the transition temperature of H-bond order/disorder transitions. Even the... 

This solution, however, is problematic because there are always isomers present in natural samples. One of these isomers (HD16Oj constitutes about 0.03% of Earth s natural water. This may seem insignificantly small, but it means that in one sip of water (about 18 mL) there are about 1.8 x 1022 molecules of HD160. That is ten million billion molecules of HD160 per sip. For this reason, it seems wrong to ignore outright the contributions of other isotopes. 

Yttrium is a light, silver-colored metal which is stable in air up to 400 C and inflammable at 500°C, producing YjOj. Yttrium also reacts with O2 in water to release H2, preferably at pH > 6. The stable (natural) yttrium isotope is Y, and there are 19 unstable isotopes and 18 isomers. The yttrium radioisotope with the longest half-life (106.6 days) is Y. Y appears... 

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