Steve Nevel. age 11. Williamsport. Penna..
What is heavy water?
Young Harold Urey was always. curious about the world around him. As a boy in Indiana and later as a young man in Montana and California. he was interested in animals and chemistry. Later. he went to Denmark to study with the great physicist. Nils Bohr. Then curiosity about atoms claimed his interest. There were certain things he just had to find out. As a boy in Indiana. he had no idea that his wonderful curiosity would win for him the greatest of all honors ‑ the Nobel Prize.
Urey was interested in isotopes. Each atom of hydrogen should be the same weight. For each is supposed to have ore proton and one electron: But careful weighing showed that the weight of a large amount of hydrogen did not come out right It weighed a little more than it should. Isotopes were suspected. For isotopes had been discovered in other element. Once in a while an atom appeared to have ark extra particle. In every other way. this isotope atom behaved exactly like its brother atoms.
Dr„ Urey wanted to separate the isotopes from hydrogen. Now hydrogen combines with carbon to make materials necessary for living fIant and animal cells. It is one of the four most plentiful elements that team up with other elements to make the thousands of substances around us. So a hydrogen isotope was important. Professor Trey. now at Columbia University. chilled a quantity of hydrogen gas to its liquid state. The temperature needed for this job was minus 423 degrees Fahrenheit. or lower.
As Urey guessed it would. the isotope hydrogen settled to the bottom of the liquid. The newly isolated substance was called heavy hydrogen. Later it was found to weigh twice as much as ordinary hydrogen. The lone proton in an atom of hydrogen weighs over 1800 times more than the lone electron. The extra particle then must be about the size of a proton. Urey isolated heavy hydrogen. also called deuterium in 1931. Experts compared notes about that extra particle in the hydrogen isotope. James Chadwich in England was studying such a particle in radioactivity.
In 1932 the new particle in both cases was identified as the neutron. This explained why the electrical balance was not upset in the deuterium atom. Protons are positive charges and electrons negative charges of electricity. The neutron is neutral.
Atoms of heavy hydrogen are present in all hydrogen and hydrogen compounds ‑ maybe one atom in a hundred is an isotopes They are present in our bodies. in our food and most plentiful in water.
All water is made up of hydrogen and oxygen. The hydrogen in heavy water ‑ or most of it ‑ is heavy hydrogen. It may be made by burning deuterium or by reducing ordinary water with an electric process. Its chemical name is deuterium oxide. It has endless uses in plant and animal studies. It is used as a tracer to reveal life processes. It is not radioactive. though neither plants nor animals can stand much of it. It is also used in industry.