- 1
The second-lightest chemical element (symbol He), with an atomic number of 2 and atomic weight of 4.002602, a colorless, odorless and inert noble gas.uncountable
- It was an enormous balloon filled with helium, that elemental gas forged from hydrogen in the nuclear furnace of the stars.
- 2
The second-lightest chemical element (symbol He), with an atomic number of 2 and atomic weight of 4.002602, a colorless, odorless and inert noble gas.; A form or sample of the element.countable
syn. E939 when used as a packaging gas