The Noble Gases

The Noble Gases are unreactive - they don't do a thing. That's why they were among the last elements to be discovered and it's also where their name comes from. Nobles, such as kings and queens don't do much, they just sit there - like a noble gas. So their name is actually a joke! HAHAAHAHAHAHAHA!

By the end of this page you should be able to:

  • To be able to identify the noble gases
  • To be able to give the chemical and physical properties of group 0
  • To be able to explain why group 0 is unreactive

Noble Gas Chemical Properties

The Noble gases are found in group 8(or 0) of the periodic table, on the far right hand side. Their names are helium, neon, argon, krypton, xenon and radon. They are extremely unreactive and colourless. This is because they have a full outer shell, this is shown in the diagrams to the right. As a rule you can assume that they don't react (small fib), they cannot form bonds and therefore always exist as single atoms (monatomic).

Group 0 - Helium, Neon, Argon, Krypton, Xenon and Radon
Decoding chemical formulae

Physical Properties

As you go down the group the physical properties of the Noble Gases change:

  • Their atomic mass increases
  • Their boiling point/melting point increases
  • Their density increases

This allows you to predict the properties of a Noble Gas, for example a common exam question gives you the boiling point of Helium and Argon and asks you to predict the boiling point of neon. Just pick a number roughly halfway between the two.

Graph Boiling Points Noble Gases

Uses of The Noble Gases

Balloons - Helium is used to make balloons float, this works because it is less dense than air.
Neon lighting - when excited the Noble gases emit vivid shades of visible light.
Argon - Welding and Lighbulbs both use Argon, they reach high temperatures and if oxygen were present things would start to burn as it is a highly reactive gas. So the air(which contains oxygen) is replaced with Argon which is unreactive (or inert).
Picture of Noble Gases Emitting Visible Light When Excited

NB: This isn't strictly on your syllabus but does come up in the exam because you have to be able to explain why a material is used for a job.

Why Does The Boiling Point Increase? (HT)

As the mass increases so does the number of electrons. This increases the strength of the intermolecular forces between the separate noble gas atoms, so more energy is needed to break them apart. Simples!

Diagram showing what intermolecular forces are
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