Associations to the word «Helium»

HELIUM, noun. (uncountable) A colorless and inert gas, and the second lightest chemical element (symbol He) with an atomic number of 2 and atomic weight of 4.002602.

HELIUM, noun. (countable) A form or sample of the element.

HELIUM BURNING, noun. (physics) (astronomy) the nucleosynthesis process, in stars where temperatures exceed 108K, in which helium is converted to carbon and subsequently to oxygen, neon and magnesium

HELIUM DATING, noun. (archaeology) a method of determining the age of rock that depends on the production of helium during the decay of various radioactive isotopes of uranium and thorium.

HELIUM FLASH, noun. (astronomy) The sudden beginning of the burning of helium in the core of stars of intermediate mass or on the surface of an accreting white dwarf.

HELIUM FUSION, noun. (physics) Nuclear fusion involving helium nuclei.

HELIUM HYDRIDE, noun. (inorganic compound) The cation HeH+

HELIUM SPEECH, noun. The effect on the timbre of speech after inhaling helium, due to the difference in the speed of sound in that gas (note - there is no difference in the pitch of the sound produced)

HELIUM STAR, noun. (star) A star which has lost most or all of its hydrogen, leaving just a core of helium.

HELIUM STARS, noun. Plural of helium star

HELIUM VARIABLE, noun. (astronomy) A star in which the strength of the helium absorption lines vary periodically; at times appearing to be a helium star.

HELIUM VARIABLES, noun. Plural of helium variable

HELIUM, noun. A very light colorless element that is one of the six inert gasses; the most difficult gas to liquefy; occurs in economically extractable amounts in certain natural gases (as those found in Texas and Kansas).