(1) In practice air is nowadays never used in deep diving, the nitrogen being replaced by helium , which is far less soluble in fat.

(2) Does it contain yet more unknown chemical elements, like helium ?

(3) Ramsay realized that argon and helium might be members of a hitherto unsuspected new group in the Periodic Table.

(4) However, if a proton is added to the hydrogen atom, a new element, helium is created.

(5) They were the ones who were always crying and throwing fits when they lost their helium balloons.

(6) Today, balloons in Japan are lifted by hot air rather than the more expensive helium or hydrogen.

(7) Other light elements that are commonly proposed for the outer core are silicon, carbon, helium , and nitrogen.

(8) Because it is chemically inert, helium was not identified on Earth until some time later, in 1895.

(9) The atomic elements heavier than hydrogen and helium could not have been produced during the inferno of the Big Bang.

(10) Eventually, there will not be any hydrogen left in the center of the Sun to make helium .

(11) During the history of our universe, more helium was made because the process that drives the stars turns hydrogen into helium .

(12) Cool the detectors with liquid nitrogen instead of solid hydrogen or liquid helium .

(13) At launch, the balloon is partially inflated with helium and expands as it rises.

(14) There he worked with Born on atomic theory, writing a joint paper with him on helium .

(15) When most of the hydrogen is fused into helium , fusion stops and and gravity again takes over.

(16) Argon is denser than air, and certainly helium , which means that it has more molecules to retain heat.

(17) During the last years of his life he worked steadily on the wave mechanics of the hydrogen and helium atom.

(18) Even though helium is twice as dense as hydrogen, this is less than one metric ton of gas.

(19) In composition it resembles a small star, with helium and hydrogen as the main gases.

(20) Over the next few years many types of laser were built, some using a mixture of helium and neon, others carbon dioxide or organic dyes.