noble gases group 18 by jon alter, parker balduf, shannon hupert, and julia lantier
TRANSCRIPT
Name Origin• Used to be called inert gases, but other
gases not included in this group are inert
• “Noble gas”- derived from German word “edelgas” (“edili”= noble)
• Alludes to the phrase “noble metals”= metals resistant to corrosion/oxidation. Thus noble refers to the gases’ low reactivity.
General Characteristics• Gases at room temperature• Monatomic gases, meaning that they exist as single atoms• Colorless • Density increases as you move vertically down the group• Melting point increases as you move vertically down the group
– Compared to other groups, very low melting points due to weak interatomic forces
• Almost entirely unreactive- they are stable due to their full outer electron shell
Helium Discovered in 1895 By Sir William Ramsay and
independently by Per Teodor Cleve & Nils Abraham Langlet
In London, England and Uppsala, Sweden respectively
Named after ‘helios,’ the Greek word for the sun
First detected in Sun’s spectrallines
The Properties of Helium
Properties Values
Density 0.0002 g/cm3
Color Colorless
Melting Point Unknown
Boiling Point -269 oC
Locations on Earth Atmosphere and underground
Abundance in the Universe 2nd most abundant
Helium Uses
Cooling medium (e.g. in the Large Hadron Collider)
Filling airships and balloons Helium-neon gas lasers (used to scan
barcodes) Arc Welding Artificial atmospheres fordeep sea divers
Neon Discovered in 1898 By Sir William Ramsay and M.W.
Travers In London, England Comes from the Greek word ‘neos,’
which means new Found in an experiment ofevaporating solid argon underreduced pressure
The Properties of Neon
Properties Values
Density 0.0008 g/cm3
Color Colorless
Melting Point -249 oC
Boiling Point -246 oC
Locations on Earth Atmosphere
Abundance in the Universe 5th most abundant
Neon Uses Neon signs, but only red ones contain
pure Neon Cryogenic refrigerate (as a liquid) High Voltage Indicators Lightning Arresters Television tubes Diving Equipment
Argon• Name origin: The name is derived from the Greek, 'argos', meaning idle. • Found in 1894 by Lord Rayleigh and William Ramsay • Was discovered as a result of trying to explain why the density of nitrogen
extracted from air differed from that obtained by the decomposition of ammonia
• Colorless and odorless gas• Melting point: -189° C• Boiling point: -186° C• Density: 0.002 g/cmᶟ• There is no reactivity for argon because it is a noble gas. • Obtained from the air as a byproduct of oxygen and nitrogen production
Krypton• Name origin: The name is derived from the Greek 'kryptos',
meaning hidden. • Discovered in 1898 by Sir William Ramsay and M.W. Travers• Does not react with anything but fluorine gas• Colorless, odorless gas• Melting point: -157° C• Boiling point: -153° C• Density: 0.003 g/cmᶟ• One of the rarest gases in the Earth’s atmosphere
Xenon Discovery date- 1898 Discovered by-Sir William Ramsay and M.W.
Travers Name origin-The name is derived from the
Greek 'xenos' meaning stranger. Characteristics:colorless, odorless,
unreactive Uses- Xenon is used in certain specialized
light sources (electronic flash bulbs used by photographers, sunbed lamps ,and bactericidal lamps used in food preparation, ruby lasers), ion propulsion systems used in satellites, manufacture of 5-fluorouracil (a drug used to treat cancer)
Natural abundance: Xenon is present in the atmosphere at a concentration of 0.086 parts per million by volume. It can also be found in the gases that evolve from certain mineral springs.
How it is obtained: extraction from liquid air.
Melting point
-112° C
Boiling point
-108° C
Density 0.005 g/cm3
Atomic number
54
Radon
Melting point
-71o C
Boiling point
-61.7o C
Density 0.009 g/cm3
Atomic number
86
• Discovery date- 1902 • Discovered by- F.E. Dorn • Name origin-The name is derived from
radium, as it was first detected as an emission from radium during radioactive decay.
• Characteristics-Radon is a colorless and odorless gas. It is chemically inert, but radioactive.
• Uses- Radon decays into radioactive polonium and alpha particles. This emitted radiation makes radon useful in cancer therapy.
• How it is obtained- Radon is produced naturally from the decay of the isotope radium-226.
• There is a detectable amount in the Earth’s atmosphere.