Chemistry Reference
In-Depth Information
Table 11.5
Uses of the noble gases.
Gas
Boiling point/°C
Argon • Tofillthespacebetweenthepanesofmoderndouble
glazing units
• Toprovideaninertatmosphereinarcweldingandin
the production of titanium metal
• Toadecreasingextent,tofillincandescentlightbulbs
(it prevented the tungsten fi lament from reacting with
oxygen in the air and forming the oxide)
Neon • Inadvertisingsigns,becauseitglowsredwhen
electricity is passed through it
• Inthehelium-neongaslaser(Figure 11.11)
• InGeiger-Müllertubes,whichareusedforthe
detection of radioactivity
Helium • Toprovideaninertatmosphereforwelding
• Asacoolantinnuclearreactors
• With20%oxygen,asabreathinggasfordeep-seadivers
• Toinflatethetyresoflargeaircraft
• Tofillairshipsandweatherballoons(Figure 11.12)
• Inthehelium-neonlaser
• Inlow-temperatureresearch,becauseofitslowboiling
point
Krypton • Inlampsusedinphotographicflashunits
• Instroboscopiclamps
• Inlampsusedinlighthouses
Figure 11.11
A helium-neon laser used in eye surgery.
Figure 11.12
Helium is used to fi ll this airship as it has a low density and
is unreactive.
Questions
1
How does oxygen help to restore life to polluted lakes?
2
Why is it important to have nitrogen in fertilisers?
3
Why is helium needed to produce an inert atmosphere for
welding?
Figure 11.9
Incubators have their own oxygen supply for babies.
●
Ammonia - an
important nitrogen-
containing chemical
Nitrogen from the air is used to manufacture
ammonia, a very important
bulk chemical
. A bulk
chemical is one that, because of its large usage
Figure 11.10
Inert nitrogen gas is used in food packaging.
