deuterium
/djuːˈtɪərɪəm
/noun [mass noun] Chemistry
A stable isotope of hydrogen with a mass approximately twice that of the usual isotope. (Symbol: D) The most easily attained fusion reaction involves fusing nuclei of the two isotopes of hydrogen, deuterium and tritium, to make nuclei of helium....
- Although many nuclei can be fused, this subject normally refers to fusion of hydrogen isotopes deuterium or tritium to form helium.
- We know that for a fact because we've measured the isotope ratio of deuterium and hydrogen.
Deuterium atoms have a neutron as well as a proton in the nucleus, and the isotope is present to about 1 part in 6,000 in naturally occurring hydrogen. It is used as a fuel in thermonuclear bombs, and heavy water (D2O) is used as a moderator in nuclear reactors.
Origin
1930s: modern Latin, from Greek deuteros 'second'.