helium [He]

Introduction

From the Greek helios meaning sun

Discovered 1872

Discovered on earth in 1895 by William Ramsay.

Discovered in the sun's spectrum in 1868 by Janssen & Lockyear.

Occurrence

• natural gas deposits within the earth
• can be isolated from air (lowest of any element)

Characteristics

• light colorless non-flammable gaseous element
• boiling point 4.2 degrees Kelvin

Uses

• inflating airships & balloons
• filling incandescent lamps
• deep sea diving, added to air to protect againts the bends
• cryogenic research

More general terms

• inert gas (noble gas, rare gas)
• bioagent

Additional terms

• periodic table

Component of

• helium/oxygen
• helium/o2
• helium/n2/o2
• heliox (helium/oxygen)