Helium

Kyle Crippa, Pd 7

History

  • discovered in 1868 by sir William Ramsay.
  • comes from the Greek word Helios which means sun.
  • origin is traced to decayed radioactive elements in rocks.
  • discovered in 1868.
  • Regarded as element on sun and unknown on earth.

Uses

  • Filling balloons to make them fly.
  • Welding when argon is too expensive.
  • inert gas shield for arc.
  • pressurizing liquid fuel rockets.
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Description

  • Second most abundant element in the universe.
  • Unreactive
  • Monoatomic gas.
  • Noble gas.
  • 0.0005% in atmosphere.
  • Atomic number is 4.
  • Colorless.
  • Non-Metallic.

Biology

  • No biological role in living things.

Geology

  • Contained in some minerals.
  • important component in the proton-proton reaction.
  • common in hotter stars.
  • obtained from wells in western worlds supply.

Properties

  • Density of solid: 214 kg m‑3
  • Melting point: 0.95 K (Kelvin)
  • Boiling point: 4.22 K (Kelvin)

Interesting facts

  • Does not react with air or water.
  • earth’s gravity can’t hold on to it.
  • discovered in suns atmosphere.
  • became available in 1928 on open market.