Physical properties of the noble gases

Group 0 contains non-metal elements placed in the vertical column on the far right of the periodic table. The elements in group 0 are called the noble gases. They exist as single atoms.

Periodic table with Group 0 coloured in redGroup 0 is on the far right-hand side of the periodic table

The noble gases show trends in their physical properties.

Boiling points

The noble gases all have low boiling points:

  • helium, at the top of group 0, has the lowest boiling point of any element
  • boiling point increases going down the group
Bar chart of the boiling points of elements in Group 0The boiling points of group 0 elements

This is because, going down group 0:

Question

Radon is situated below xenon in group 0. Predict the likely boiling point of radon.

The actual boiling point of radon is -61.7˚C. An estimate would lie midway between -100˚C and -50˚C based on the shape of the graph.

Densities

The density of a substance is its mass per unit volume. For example, a small piece of a substance with a high mass has a high density.

The particles in gases are widely spaced, so the noble gases have low densities:

  • helium, at the top of group 0, has the lowest density in the group
  • density increases going down the group
Bar chart of the density of six Group 0 elements.The densities of group 0 elements