(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.

(physics) The liquified form of helium that does not solidify even at absolute zero; it shows unusual properties, such as superfluidity, due to quantum effects.

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

plural of helium flash

plural of helium star

plural of helium variable

(physics) The normal isotope of helium, ⁴₂He, that has two neutrons

(physics) The rare isotope of helium, ³₂He, that has a single neutron

(physics) Having the electronic structure of a helium atom

Synonym of helide