Elements in the same group of the periodic table show trends in physical properties, such as boiling point. They have the same number of electrons in their outer shell, so they are similar in their chemical properties.
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.
The noble gases show trends in their physical properties.
The noble gases all have low boiling points:
This is because, going down group 0:
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.