See Also: helium-3(medicine)
helium-4(medicine)
helium(medicine)
helium(dictionary)
helium(encyclopedia)
helium(dictionary)
helium speech(medicine)
helium dating(encyclopedia)

helium (iou)



helium noun. L19.
[from Greek helios sun + -IUM: the element was inferred to exist from an emission line in the sun's spectrum.]
A colourless odourless gaseous chemical element, atomic no. 2, which is the lightest of the noble gases and is present in traces in the earth's atmosphere. (Symbol He.)