the noble gases

© Boardworks Ltd 2003

THE NOBLE GASES


Group 0 the noble gases

Coming after Group 7, you might expect these to be called Group 8 – and in some books they are.

Group 0 is a better name though – because that’s what they do!

H

Li

Na

K

Rb

Cs

Fr

Be

Sc Ti

Mg

V Cr Mn Fe Co Ni Cu Zn Ga Ge Se BrCa Kr

Y Zr Nb Mo Tc Ru Pd Ag Cd In Sn SbSr TeRh

Ba Hf Ta W Re Os Ir Au Hg Tl Pb Bi PoLa AtPt

Ra Rf Db Sg Bh Hs Mt ? ?Ac ?

Al P

N O

S Cl

F Ne

Ar

Rn

I

Si

Xe

He

B C

AsKr

Ne

Ar

Rn

Xe

He

Gp 0


Electron Structure and Reactivity

All the elements in this group have fully occupied outer shells.fully occupied outer shells.

They are the least chemically least chemically reactive elements.reactive elements. The stable arrangement means that the noble gases do not form chemical bonds with each other or other elements.

They are monatomicmonatomic which means they exist as individual atoms.

Ar

Ne

He 2

2,8

2,8,8


Uses of Noble Gases

You might think that a group of elements that have almost no reactions would have few uses.

You would be wrong! They have many uses, mostly based upon their ability to prevent other (undesirable) reactions taking place.


Uses of Helium

- Balloons (big and small).

- Protective gas for growing silicon crystals in silicon chip manufacture.

- - Rare documents preservation (i.e.

US Declaration of Independence).- - Pressurizing agent for liquid fuel

rockets (inert so won't react).

- Coolant for the super-conductors used in body scanners.


Uses of Neon

- Fluorescent lights and ‘neon’ signs.

- TV tubes.

- Neon lasers.


Uses of Argon

- Used to fill light bulbs because the filament will not react with argon.

- Used as an inert gas shield for arc welding and cutting especially metals easily damaged by oxygen such as aluminium & stainless steel.

- Argon is involved in dating the ages of rocks by potassium-argon dating.


Ne

Ar

He

Match the gas with the use


Patterns: Density!

- There can be few chemical patterns for a group as unreactive as this.

- There are still trends in physical properties

0.17

0.84

1.66

3.46

5.45

8.9

0

Density g/dm-3

Rn

Xe

Kr

Ar

Ne

He


- There are also trends in boiling point.

- Can you predict the B.Pts of Kr Xe and Rn?

-269

-246

-186

-152

-108

-62

-300 -200 -100 0

Boiling PointC

Rn

Xe

Kr

Ar

Ne

He


Which is NOTNOT a true statement about the noble gases?

A. They contain shells that are full or emptyB. They are monatomic gasesC. They are un-reactive.D. They are lighter than air


Which gas is used in normal light bulbs?

A. HeliumB. NeonC. ArgonD. Krypton


Which gas is used in airships?



Which gas is used in red fluorescent lights?



Which gas is used to provide a shield ofinert gas during arc welding of metals likealuminium?


the noble gases

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