Definition of nebulium in English:

nebulium

Pronunciation /nəˈbyo͞olēəm/ /nəˈbjuliəm/ /neˈbyo͞olēəm/ /nɛˈbjuliəm/

noun

historical Chemistry
  • A hypothetical chemical element proposed in the 1860s to explain certain lines in the spectra of nebulae, later discovered to arise from forbidden transitions in oxygen and nitrogen ions.

    as modifier ‘nebulium lines’
    • ‘The hypothetical nebulium was simply the signature of ordinary oxygen doing extraordinary things.’
    • ‘Coronium and nebulium were both, in the event, figments of the astronomers' imaginations.’
    • ‘They called this unknown ‘new’ element nebulium, but modern astronomy has since shown it to be a rare form of superheated oxygen.’
    • ‘And, in the twentieth century, we learned that nebulium was actually ionized oxygen and nitrogen.’
    • ‘He proposed that a new and unknown element, ‘nebulium’, was responsible for these lines.’

Origin

Late 19th century from nebula+ -ium.