The Noble Gases Group 18

1. The Noble GasesGroup 18 Audrey Looby Riley Stanford Janine Tobia

2. Meet The Family! • Helium-He 1s² • Neon-Ne • Argon-Ar • Krypton-Kr • Xenon-Xe • Radon-Rn np⁶ n=row #

3. Properties • All are gases and non-metals • Low reactivity; helium, neon, and argon form no known compounds • Boil at extremely low temperatures • Non-conductive • Complete valence shells • All are found as free elements

4. Helium • Lowest boiling point of all the elements • First identified in the sun’s spectrum • Isolated from uranium ores (alpha particles that are emitted pick up electrons) • Used by divers to dilute the oxygen that they breathe and in balloons • Obtained from liquid air • From the Greek, helios, meaning ‘the sun’

5. Neon • Coming from the word neosmeaning ‘new’ • Produces the red light in neon signs • Liquid neon used as a cryogenic refrigerant, over 40 times the refrigeration capacity of helium, over 3 times the refrigeration capacity of liquid hydrogen • 1/65000 parts of the atmosphere

6. Argon • First noble gas to be discovered (1894) • Argon means ‘the lazy one’ in Greek • Used in electric lights, photo tubes, glow tubes, and lasers • Also used for welding • Used to protect from radioactive elements • Colorless, tasteless, and odorless • Makes up 1% of the Earth’s atmosphere

7. Krypton • Reactive with Fluorine; only known compound is KrF₂ • Not very useful commercially • Comes from the word kryptos meaning ‘hidden’

8. Xenon • Has a wide range of compounds with O and Fluorine • First compound discovered in 1962 by Neil Bartlett • Means ‘stranger’ in Greek • Used in strobe lamps • Takes up 1/20 million of the atmosphere

9. Radon • Very radioactive • Can form compounds, but can’t be studied due to its high reactivity • Used to treat cancer • Heaviest of the noble gases • When its cooled below its freezing point, it displays beautiful phosphorescence • Average concentration is 1/sextillion parts of air • Naturally occurs in some spring waters

10. The Noble Gases… • …like nobility, are nonreactive, and tend to remain apart. • And now for a simple overview….

12. The End!