From Sanskrit, meaning "two".
- (chemistry, dated) A designation prefix for undiscovered chemical elements lying two periods under a known element in the periodic table. (For example, rhenium was called dwi-manganese before its discovery in 1926.)
Current official IUPAC practice is to use a systematic element name based on the atomic number of the element as the provisional name, instead of being based on its position in the periodic table as these prefixes require.
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|Cardinal : dwi-|