|another name for deuterium|
|a chattering or flighty, light-headed person.|
|an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.|
heavy hydrogen n.
isotope of hydrogen with atomic weight of approximately 2. Its nucleus, consisting of one proton and one neutron, has double the mass of the nucleus of ordinary hydrogen. Deuterium is a stable atomic species found in natural hydrogen compounds to the extent of 0.014 to 0.015 percent.
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