Group 0: The Noble Gases (AQA GCSE Chemistry)

The elements in Group 0 of the Periodic Table are called the noble gases

Noble gases are:

• Non-metals

• Monatomic (exist as single atoms)

• Colourless and non-flammable gases at room temperature

Most elements participate in reactions to complete their outer shells by losing, gaining, or sharing electrons

Group 0 elements do not do this because they have full outer shells of electrons 

• They are therefore unreactive (inert) and do not form molecules easily

Most noble gases have 8 electrons in their outer shell, except helium which has 2

Electronic configurations of the noble gases:

• He = 2

• Ne = 2, 8

• Ar =  2, 8, 8

• Kr =  2, 8, 18, 8

• Xe = 2, 8, 18, 18, 8

Being chemically inert makes noble gases useful for many applications

• Argon is used to provide an inert atmosphere for welding

• Argon is also used to fill light bulbs

There are trends in the physical properties of the noble gases

The noble gases have very low melting and boiling points 

Going down the group melting and boiling point increases because:

• The atoms get larger as you move down the group and their relative atomic mass increases

• This leads to an increase in intermolecular forces between atoms

• Therefore more energy is needed to overcome these

Although elements further down the group have higher boiling points, they still lie below 0 ºC.

Helium has the lowest boiling point of all known elements at -269 ºC, while radon boils at around -60 ºC.